Diamond Clarity

Diamond Clarity

Buying Tips

Flawless
I3-I2
I1
SI2
SI1
VS2
VS1
VVS2
VVS1
IF
FL
Flawless
FL: No visible blemishes, < 1% of diamonds.
Inclusions are not visible under 10X, rarest clarity grade.

 

Diamond Clarity Grade Chart

FL & IF

FL, IF Graded Diamond

Flawless, Internally Flawless

Under 10x magnification, inclusions are not visible, rarest clarity grade.

  • FL: No visible blemishes, <1% of diamonds
  • IF: Very slight blemishes, <3% of diamonds
VVS1, VVS2

VVS Graded Diamond

Very, Very Slightly Included

Characteristics miniscule and difficult to see under 10x magnification, even to a trained eye.

  • VVS1: Few miniscule inclusions
  • VVS2: Slightly more miniscule inclusions
VS1, VS2

VS Graded Diamond

Very Slightly Included

Minor inclusions ranging from difficult to somewhat easy to see at 10x magnification.

  • VS1: Difficult to see minor inclusions
  • VS2: Somewhat easier to see minor inclusions
SI1, SI2

SI Graded Diamond

Slightly Included

Inclusions noticeable at 10x. Best value. SI2 inclusions may be detectable to a discerning unaided eye.

  • SI1: Inclusions occasionally visible to the keen eye without magnification
  • SI2: Inclusions typically visible from the pavilion, and often seen from the top, without magnification
I1

I1 Graded Diamond

Included

Diamonds may have more obvious inclusions at 10X and may be visible to the eye. Blue Nile offers a limited selection of jewelry with I1 clarity diamonds..

  • I1: Loose diamonds of this grade not offered by Blue Nile
I2, I3

>I2, I3 Graded Diamond

Clarity grades not carried by Blue Nile.

Inclusions are obvious under 10x magnification, usually visible to the unaided eye.

More Expert Tips

  • Select an “eye-clean” diamond – one that has no imperfections visible to the unaided-eye through the crown. An excellent value, diamonds of this clarity are much less expensive than flawless (FL) or internally flawless (IF) diamonds, which are extremely rare and command higher prices.
  • If you’re considering a diamond with an SI clarity grade, call to speak to a diamond and jewelry consultant who will review the diamond to ensure the imperfections are not visible to the unaided eye.

https://www.bluenile.com/education/diamonds/clarity?gclid=CIvn1bDdp9YCFQktaQodo5gBuQ&click_id=494646443

20 Things You Didn’t Know About… Crystals

20 Things You Didn’t Know About… Crystals

The ones inside comets forged by the Sun, the ones buried under Manhattan, and the “crystal” ones that aren’t crystal at all

crystal
iStockphoto

 It’s all about the rhythm: Crystals are repeating, three-dimensional arrangements of atoms, ions, or molecules.

Almost any solid material can crystallize—even DNA. Chemists from New York University, Purdue University, and the Argonne National Laboratory recently created DNA crystals large enough to see with the naked eye. The work could have applications in nanoelectronics and drug development.

One thing that is not a crystal: leaded “crystal” glass, like the vases that so many newlyweds dread. (Glass consists of atoms or molecules all in a jumble, not in the well-patterned order that defines a crystal.)

 The oldest known pieces of our planet’s surface are 4.4-billion-year-old zircon crystals from the Jack Hills of western Australia.

5  The center of the earth was once thought to be a single, 1,500-mile-wide iron crystal. Seismic studies now show that the inner core is not a single solid but perhaps an aggregate of smaller crystals.

 Tiny silicate crystals, which need high temperatures to form, have been found inside icy comets from the solar system’s distant, chilly edges. Powerful flares from the sun may have provided the necessary heat.

7  In Chihuahua, 
Mexico, a limestone cavern 1,000 feet below the surface contains the largest crystals in the world: glittering gypsum formations up to 6 feet in diameter and 36 feet long, weighing as much as 55 tons. You may be sitting in a gypsum cave right now: It is a primary component of drywall.

 Are the streets of New York paved with gold? No, but the bedrock schist beneath them is studded with opal, beryl, chrysoberyl, garnet, and three kinds of tourmaline.

10  In 1885 a garnet weighing nearly 10 pounds was discovered beneath 35th Street near Broadway, close to today’s Macy’s store. According to urban lore, it was unearthed either during subway construction or by a laborer digging a sewer.

11 Cheaper by the pound: The so-called Subway Garnet was sold within a day, reportedly for $100—just $2,300 in today’s dollars.

12  The unit of measure for gemstones had humble beginnings. “Carat” comes from the Greek keration, or “carob bean,” which was used as a standard for weighing small quantities. It is equivalent to 200 milligrams, or about 0.007 ounce.

13  When Richard Burton bought Elizabeth Taylor the heart-shaped Taj-Mahal diamond, he is said to have bragged, “It has so many carats, it’s almost a turnip.”

14 A “fancy intense pink” diamond recently set a world record when it was purchased at auction for $46 million by a London jeweler.

15  The Cullinan diamond is the largest known gem diamond—or, actually, was. It weighed 3,106 carats, or nearly a pound and a half, when it was discovered in South Africa in 1905, but it has since been cut into more than 100 stones.

16  The Cullinan stones, all flawless, are now part of the British Regalia. The largest, a 530-carat behemoth, is set in one of the British royal scepters.

17  For the rest of us, there is crystallized sodium chloride, otherwise known as salt. We are literally awash in it: If the water were evaporated from the world’s oceans, we’d be left with 4.5 million cubic miles of salt, equivalent to a cube measuring 165 miles on each side.

18  Another crystal for commoners: sugar. Each American eats an average of more than 130 pounds of it per year.

19  As if sugar’s ties to obesity and tooth decay weren’t enough, new research out of Imperial College London suggests that it contributes to high blood pressure, too.

20 Snow is near-pure crystallized water, but when it collects on the ground it acts as a reservoir for atmospheric pollutants such as mercury and soot. So you probably shouldn’t eat the white snow either.

http://discovermagazine.com/2011/may/05-things-you-didnt-know-about-crystals

Don’t Get Fixated On Spot Price When Buying Silver Coins

Don’t Get Fixated On Spot Price When Buying Silver Coins

Silver investors tend to check the current spot price before making a purchase of silver coins. That’s a logical starting point, as the cost for physical metal is usually – but not always – related to spot.

Don’t expect former premiums to remain in place when spot plunges. Why does this happen? Lower prices means fewer sellers, so dealers have to raise their bids in relation to spot to purchase new supplies.

I would be very thrilled to have a pre-1965 silver dime for every time I’ve heard someone mindlessly blather about how they expected to obtain silver at around spot right after prices took a substantial plunge. Since spot (a paper price) can be and is manipulated by traders, it’s not a rock-solid indicator of what the metal is going to cost in the real world. Think of spot as theory and retail prices as reality. In precious metals and life in general, reality rules and theory drools.

90% silver coinsSometimes demand for the real thing increases faster than spot prices. That means some short-term hikes in premiums. We’re not talking about a massive surge in buying, but a moderate bump in retail demand. Since there are no great hoards of physical product waiting to be dumped into the hands of the general public, these moves take place for a week or two every few years.

Web sites and chat rooms are full of people who say they will buy silver coins once the price drops a few dollars or more. Those who make such statements usually assume they will be able to obtain the metal at something near spot, but recent developments prove once again that reality stomps on theory when dealing with physical product.

Bags ($1,000 face value, or 715 troy ounces) of pre-1965 dimes, quarters and half dollars sold for three to four percent above melt in December 2012 when silver was in the US$33 range. At that time, buy prices ranged just below spot to spot.

Fast forward to now for an entirely different situation. Two bullion industry market makers are currently paying significant premiums over spot for 90 percent silver.

Even those who are willing to pay the new levels may not be able to acquire silver. “Out of stock” is a common phrase at silver coin web site listings, and the same sad news has been dispensed to many potential buyers at local coin shops and over the phone.

One small silver coin dealer obtains much of his product from a large Midwestern source. An order for $500 face was placed and accepted last week. When the buyer went to pick up his order, he was told that just $250 face was available. Since this wholesaler is known for his utter dependability, this was something of a surprise.

silver coins, bullion coinsThe supply/demand and price situation in silver Eagles and Maple Leafs is similar to what is happening with 90 percent. Premiums and prices are moving up, and those who hesitate need to get out of the way as others in line are willing to pay the going rate.

Need more proof that spot numbers are not the ultimate guide to real world pricing? What if spot dropped to $15 tomorrow? Do you think that you could obtain silver for $5 or $6 an ounce over spot? Only the delusional and uninformed would expect to find silver in such a scenario.

Spot will have less influence on the retail market as the frequent manipulation of paper prices continues and public awareness of such trickery expands. Toss in growth in demand for physical silver coins coupled with tight supplies, and precious metals buyers may have to do a little work to determine fair prices in the future.

How can a person find such information? It’s very easy in the information age. Check a few major dealer web sites to get their buy/sell spreads. When postage fees are added to the total, small buyers can do as well or better making purchases of silver coins at local shops rather than going the mail-order route.

So when is the right time to buy silver, and what would be a fair premium to pay? That’s a decision (emphasis on being proactive rather than passive) every individual has to make. Keep in mind that buying silver isn’t an all or nothing proposition.

What if someone wants to spend a few thousand dollars on the metal, but they aren’t sure about pulling the trigger? Put a portion of the funds into silver and see what develops in the future. Don’t expect to hit a home run on every buy, but a steady stream of singles and doubles will win the silver game in the long run.

Don’t Get Fixated On Spot Price When Buying Silver Coins

8 Valuable Coins That Could Be Hiding in Your Change

8 Valuable Coins That Could Be Hiding in Your Change

  
You never know what a coin might amount to.
You never know what a coin might amount to.
IMAGE: FLICKR, QUINN DOMBROWSKI
Take a closer look before you dump that handful of pennies and nickels into the tip jar — you don’t need to find a Revolutionary War-era coin to make a fortune from your change.They’re harder to find each year, but there are several valuable coins floating around that aren’t all that old. They’re often valuable for vastly different reasons — like the World War II-era coins minted from atypical metals, or double-printed pennies — but each one is easy to miss if you’re not paying attention.

Check out these eight coins that are worth a lot more than their intended value.

1. 2004 Wisconsin state quarter with extra leaf

Value: Up to $300

Find an average Wisconsin state quarter from 2004, and that will get you one-fourth of a bag of chips. Find one with either the high or low leaf error, and you can get a whole lot more.

The 50 State Quarters series ran from 1999 until 2008, with special designs representing each state. Wisconsin’s quarter came out in 2004; the reverse design features a cow, a wheel of cheese and a partially husked ear of corn lurking in the back.

765px-2004_WI_Proof
It would be too easy to make a corny joke about this coin. Too cheesy?

However, some the coins have an extra line below the front left leaf, which looks like another leaf entirely. There are two varieties you should be looking out for: the high leaf and low leaf.

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2. 1995 double die penny

Value: $20 – $50

1995ddo1liberty-435x165
1995ddo1inGOD-437x153

This penny has a double-printed obverse (heads side) that makes the “LIBERTY” and “IN GOD WE TRUST” look blurry. The error has happened before, in 1969 and 1972, and those versions of the coins are much more valuable.

3. 1942-1945 silver nickel

Value: 56 cents – $12.25

During World War II, the United States needed to save as much nickel as possible for military uses. Consequently, it started minting nickels made of 35% silver. Melting down pennies and nickels is a federal offense, but the coin might still fetch you enough for a decent lunch, if it’s in good condition.

4. 1943 steel penny

Value: 45 cents – $10

1943 Steel Penny
Pennies were made from steel in 1943 only.

IMAGE: UNITED STATES MINT

Pennies were made from steel during wartime, for the same reasons nickels were made partially from silver — steel pennies helped preserve copper for World War II. However, the switch only lasted one year.

5. Ben Franklin half-dollar

Value: $12 – $125

Franklin Half-Dollar
Easy to notice, but hard to find.

IMAGE: UNITED STATES MINT

In 1948, the U.S. mint began circulating half-dollar coins with images of Ben Franklin and an eagle — which is funny, considering Franklin opposed the bald eagle’s nomination as the nation’s bird, in favor of a wild turkey.

Franklin’s portrait on the coin was replaced by John F. Kennedy in 1964, following the president’s 1963 assassination.

6. 1932-1964 silver quarter

Value: $7 – $65

Between 1932 and 1964, quarters were 90% silver and 10% copper. These silver quarters look like any pre-state quarter 25-cent piece, but are worth a lot more if they’re in the right condition.

7. ‘In God We Rust’ 2005 Kansas state quarter

Value: Up to $100

rust
Remember: Always clean your machine.

IMAGE: ABOUT.COM

While it might seem like a mint employee’s rogue political statement, these coins are actually just the result of grease preventing a clean pressing.

8. Presidential dollar coin with lettering errors

Value: $20 – $45

gw
These Washington dollars are missing key inscriptions.

IMAGE: NGC

In 2007, the U.S. Mint began printing a series of dollar coins featuring presidents. Many of the early coins, especially those with George Washington, have errant or missing lettering along the edge of the coin.

 

http://mashable.com/2014/08/25/valuable-coins/#B_NvmAVLIGqw

15 Most Expensive Watch Brands in the World

15 Most Expensive Watch Brands in the World

15 Most Expensive Watch Brands in the World

As we all know wristwatch is one of the most important accessories in men’s or women’s wardrobe. The watch is the one of the best accessory in terms of style and you can choose from a simple steel watch to a unique watch in diamonds and jewel encrusted one.  Whatever your style maybe a wristwatch on your hand will always make you look elegant and stylish.

There are a lot of watch manufactures and brands, from standard ones to top-quality luxury ones.  If you are self-sufficient person and you have a lot of money and you want to buy high end luxury watch that will be instantly spotted and recognized by others, then there are many expensive watch brands that you can choose from.  And the first question comes to mind is “What brand has the most expensive watches?”

Not long ago I’ve posted a list of 15 Most expensive wristwatches that costs over 1 million dollar and you can see that in the list some expensive watch brands have many expansive watch models. But there are many other watch makers that have expensive watches.

The most expensive watch brands in the world are as follows. But don’t forget that every year the order can be different because new timepieces are released by the watch makers.

[ordered_list style=”decimal”]

  1. Patek Philippe
  2. Vacheron Constantin
  3. Jaeger-LeCoultre
  4. Blancpain
  5. Cartier
  6. Ulysse Nardin
  7. Chopard
  8. Audemars Piguet
  9. Hublot
  10. Piaget
  11. Girard-Perregaux
  12. Rolex
  13. Omega
  14. A. Lange & Söhne
  15. TAG Heuer

[/ordered_list]

And here a some of interesting expensive watches of this brands:

most-expensive-watch-Patek-Philippe-Sky-Moon-Tourbillon
Patek Philippe – Sky Moon Tourbillon (Price: ~ $5,6 million)
[hr]
Vacheron-Constantin-Grand-Complication-pocket-watch
Vacheron Constantin – Grand Complication pocket watch (Price: ~ $1,8 million)
[hr]
most-expensive-watch-Joaillerie-101-Manchette
Jaeger-LeCoultre – Joaillerie 101 Manchette (considered the most expensive watch in world, price unknown)
[hr]
most-expensive-watch-Blancpain-Tourbillion-Diamants
Blancpain – Tourbillion Diamants (Price: ~ $1,812 million)
[hr]
most-expensive-watch-Cartier-Phoenix-shaped-watch
Cartier – Phoenix-shaped watch (Price:  ~ $2,755 million)

Some of the timepieces made by this expensive watch brands are the best watches with unique design, top quality, complicated movement and features that other watches don’t have. I know that there are other expensive watch brands but this is best watch brands in the world.

http://www.tiptopwatches.com/watch-facts/15-expensive-watch-brands-world.html

“Watches 101”

“Watches 101”What’s the best way to store a watch?
What’s a “movement”?
What is the legal definition of a Swiss watch?
Which leads to the question: What is a Swiss movement? They have a ready answer, of course:
What does the word “Geneve” on a watch mean?
What’s the difference between a mechanical movement and a quartz movement? 
What does 17-jewel movement mean?
What does the word “chronometer” mean?
Who is the COSC and what do they do?
What’s a “chronograph”?
What do the letters “T” and “O” mean on my watch?
It is possible that this comes from the French word for gold, Or, is it true that tritium is radioactive? 
Is there such thing as a completely waterproof watch?
What does “Shock Resistant” mean?
Is it true that only a diamond will scratch a sapphire crystal face?
What’s the best way to store a watch?
Storing a luxury watch properly requires a little extra care. Diamonds and other gemstones are hard enough to scratch metal jewelry and to mar the surfaces of other stones they come in contact with. Store diamond and/or gold watches in their own individual soft cloth pouches, place them in a jewelry box that has separate compartments for each piece or store them in their original box.What’s a “movement”? 
A movement is the mechanism that actually calculates the passage of time–the “guts” of the watch, if you will. Like the engine and transmission of a car, watch movements are so fundamental to the quality of the watch that they are often manufactured by separate companies, or by the same company in a different factory. The movement is also the part of the watch which is usually covered by a warranty–much like the “engine and drivetrain” warranties that come with new cars.

What is the legal definition of a Swiss watch? 
As the universally-acknowledged manufacturers of the world’s best watches, the Swiss are understandably rather persnickety about what watches qualify as “Swiss.” To protect the integrity of their good name, several organizations have formed with the specific intention of regulating quality and defining standards for the industry. The Federation of the Swiss Watch Industry has produced a list of “Verordnung Swiss Made” rules that state that a Swiss watch must:

  • Have a Swiss movement that
  • Was set into its case in Switzerland
  • By a manufacturer of Swiss origin.

Which leads to the question: What is a Swiss movement? They have a ready answer, of course:
It must have been assembled in Switzerland under the supervision of a Swiss factory and the parts of the movement that are Swiss in origin must constitute at least 50% of the movement’s total value. Movements that meet these exacting requirements earn the right to be stamped with the word “Swiss.” Sometimes the stamp will instead say “Suisse,” “Swiss Quartz,” “Swiss Made,” “Produit Suisse,” or “Fabrique en Suisse.” These all mean the same thing. However, if the case is not of Swiss origin, then this inscription cannot be visible–it must be concealed by the case. However, the case may be stamped with the words “Swiss Movement” to indicate that it’s Swiss on the inside, if not the outside. In the case of the reverse–a non-Swiss movement in a Swiss case, only the words “Swiss Case” are permitted.

What does the word “Geneve” on a watch mean?
Just as Geneva is a more specific location than Switzerland, the designation “Geneve” is a more exacting mark of prestige given to watches by the Bureau de controle des Montres de Geneva. To qualify, in addition to matching all the above criterion for a Swiss watch, it must have had one of its major manufacturing steps take place within the Canton of Geneva. The theory is that at least 50% percent of the manufacturing costs will have been incurred “locally,” protecting the trade and ensuring quality assembly.

What’s the difference between a mechanical movement and a quartz movement?
Mechanical movements are what most people think of when they talk about the fine art of watch making–a precise, intricate system of tiny gears and springs which use mechanical energy to operate. These watches have a mainspring, which is wound either by hand or by “automatic movement” (self winding). The spring power is then transferred to the hands of the watch via a precise timing mechanism known as a balance.

A quartz movement is a simpler, less expensive timing mechanism which regulates time by sending an electric current from a battery to a tiny quartz crystal, which vibrates at precise and predictable rates–32,768 cycles per second to be exact. Quartz movements are superbly accurate and reliable. Because they can be mass-produced, quartz movements are used in everything from clock radios and digital watches to some very fine timepieces. However, what is gained in efficiency is lost in elegance, according to some epicureans.

Interestingly enough, the first quartz watch, introduced by Seiko in 1969, cost over a thousand dollars!

What does 17-jewel movement mean?
In spring-powered mechanical watches, conservation of energy is practically an art form. To reduce friction, many of the spaces between gears are set with tiny synthetic gem crystals, which resist temperature changes better than metal and hold lubricant much longer.

What does the word “chronometer” mean?
Strictly speaking, anything that measures time is a chronometer (chronos = time, meter = measure). An hourglass or a sundial is technically a chronometer. However, in modern watchmaking the term “chronometer” is a specific designation of accuracy, assigned only to high-quality watch movements that have been tested by the COSC.

Who is the COSC and what do they do?
The Control Officile Suisse de Chronometers is a Swiss testing laboratory that certifies watches, or rather their movements, as “chronometers.” Each movement is individually tested over a 15-day period in different positions and temperatures, and passes only if it shows a loss of fewer than five seconds per day. Watches that have certified movements will usually be stamped with an inscription that says “Chronometer,” “Certified Chronometer,” or “Superlative Chronometer Officially Certified.”

What’s a “chronograph”?
By definition a chronograph “records time.” In modern watches this refers to a stopwatch function of some sort.

What do the letters “T” and “O” mean on my watch?
The letter “T” on the face of a watch stands for tritium, the greenish-white substance on the hands and numbers that glows in the dark. The letter “O” means that the indices on the dial are made of gold.

It is possible that this comes from the French word for gold, Or, is it true that tritium is radioactive?
Although tritium is a radioactive substance, the amount of radiation from tritium-coated watch faces is less than 25milliCuries, which isn’t even enough to penetrate the watch case or crystal.

Is there such thing as a completely waterproof watch?
Not really–in fact it’s not even a legal term in the US anymore, and for good reason. Even deep-sea submarines have maximum depths beyond which they cannot safely travel. That’s because deeper water means higher water pressure, and eventually water pressure will break the windows. Watches are rated for “water resistance,” which is an evaluation of how much water pressure the moisture seals can withstand. Most watches are rated to 50 meters, which is more than most of us will ever need. Sport and diving watches are often rated to 200 meters or more. Ironically, humans can only safely dive to about half that depth, and extremely high depth ratings are more an indicator of craftsmanship and status than actual utility. Water resistance is also measured in ATM, or atmospheres. One atmosphere is equivalent to 10 meters.

What does “Shock Resistant” mean?
Shock resistance is an American government standard of durability which means that the watch can survive a drop of three feet onto a wooden floor.

Is it true that only a diamond will scratch a sapphire crystal face?
Not quite. Another sapphire or ruby will scratch it. Also remember that scratch-proof is not hatter-proof. A sapphire crystal is remarkably durable, but far from impervious. It’s best to treat a quality watch like any other piece of finely-crafted jewelry.

http://www.watchesandbeyond.com/watches101.asp#top

Nine Shiny Facts About the Metal Silver

Nine Shiny Facts About the Metal Silver

January 24, 2014 by KIDS DISCOVER

SilverIt’s a precious metal found in lots of jewelry, but silver has plenty of everyday uses in electronics, medicine, paint, photography, currency, clothing, and more. Here are some facts you probably didn’t know about silver … .

Name: Its name comes from the Anglo-Saxon seolfor, but silver’s chemical symbol, Ag, is based on its Latin name, argentum.

Industry: Silver conducts heat and electricity better than all other elements, which is why it’s used in things like solar panels, electrical circuits, and rear window defoggers.

Heat: Silver melts at 1,763.2 degrees Fahrenheit, and it boils at 3,924 degrees Fahrenheit. So yeah, go ahead … you can stir soup with the good silverware.

Tarnish: That dark stuff that appears on silver and makes it need polishing is actually silver sulfide, a compound formed when silver interacts with sulfur in the air … or in eggs. Which is why some people don’t use good silverware with eggs or mayonnaise.

Coins: Until 1964, all United States dimes, quarters, half-dollars, and dollar coins contained 90 percent silver. So keep your eyes peeled when you get change at the market, because every now and then you can still find a real silver coin.

Bendiness: After gold, silver is the easiest metal to work with — you can stretch it into superfine wire or pound it into superthin foil (would you believe 150 times thinner than paper?).

Weather: Silver can make it rain! When silver iodide is dropped onto clouds in a process called “seeding,” it often provokes a rainfall.

Medicine: Silver is great at killing bacteria, which is why it’s sometimes used in wound dressings at burn units. And bacteria don’t adapt to silver’s germicidal properties the way they become immune to antibiotics.

Hygiene: You know what else bacteria do? They cause B.O. That’s why some fancy athletic clothing contains tiny silver fibers, which reduce or eliminate smells. But rubbing earrings or spoons under your arms in the morning really won’t help.

 

http://www.kidsdiscover.com/quick-reads/nine-shiny-facts-metal-silver/

Jewelry Metals 101: Most Commonly Used Jewelry Metals

Jewelry Metals 101: Most Commonly Used Jewelry Metals


Jewelers, both professional and amateur, have used just about every type of metal in existence in their creations. As new alloys and metals are adapted to jewelry making, such as titanium and stainless steel, they are also eagerly embraced and worked into beautiful creations for men and women. While fashion trends using unique and trendy metals come and go, three jewelry metals have stood the test of time and continue to have a strong presence in modern jewelry.  They are Gold, Silver, and Platinum.

These three metals and the alloys that utilize them are referred to as the Noble Metals.  Noble Metals have four properties in common.

  1. They are precious metals and are also used as currency (a store of value) because of their intrinsic value.
  2. They are found worldwide, but not in large enough quantities to render them less valuable.
  3. Noble Metals have properties that lend themselves to jewelry making, including malleability and corrosion resistance.
  4. These metals are considered beautiful, sensuous, and glamorous, which increases their appeal. Because of all of these properties, the Noble Metals – gold, silver, and platinum – are frequently used in jewelry making.

Gold

Coveted for its beauty, gold has long captivated the human psyche and is considered the most sensuous metal. Jewelry designers and makers find gold easy to work with and prefer it to other metals because it never tarnishes. Gold is perhaps the most workable metal, which is another reason designers enjoy working with it. A single ounce of gold can be stretched into a thread more than 50 miles long or rolled flat into a sheet that covers 100 square feet in area!

Another reason gold is coveted by both consumers and designers is that it lasts indefinitely, especially if properly cared for. Recent studies show that gold originated in the far reaches of the universe billions of years ago and arrived on earth in its infancy. It does not oxidize or corrode and only a handful of rare acids or hot chlorine bleach can damage gold. Gold can also be reused by melting down old gold objects and reforming the gold into new pieces. For example, old coins and broken pieces of jewelry can be melted down and reused to make a brand new piece of gold jewelry.

Gold Alloys

Despite gold’s desirable properties, it does have one significant drawback. It is soft, which means it wears easily. By mixing gold with other metals, or alloying it, gold is made stronger, which makes it durable enough to wear more often without experiencing wear. A variety of metals are commonly used to alloy gold, including silver, copper, nickel, iron, zinc, tin, manganese, cadmium, and titanium. Along with enhancing gold’s strength, alloying gold with other metals changes some of gold’s other properties as well. This is why some gold alloys stain people’s skin or cause an allergic reaction. The reaction is not caused by the gold itself, but by the other metals it is mixed with.

While pure gold is also used in jewelry making, it dents and shows wear easily, which is why most people choose not to wear 100% gold jewelry on a regular basis. When discussing gold and its alloys, the term karat is used to indicate the purity of the gold (Not to be confused with carat, which is a unit of measurement used to describe gemstone weight). Pure gold, which contains no other metals, is termed 24 karat gold. A gold alloy that is 50% gold and 50% other metals is 12 karat gold because it is only half pure gold. Alloys used in jewelry making range from 9 karat gold, which is approximately 37% gold, to 24 karat gold, and are required to be stamped and hallmarked according to purity. A newer alloy becoming popular on the jewelry scene is made of 99% gold and 1% titanium, allowing the alloy to retain nearly all of its gold color while providing improved durability.

Gold Alloy      
Karat Parts Gold Percent Gold Other Marks
24 24/24 100% 1000
18 18/24 75% 740
14 14/24 58.33% 585
12 12/24 50% 500
10 10/24 41.60% 416
Colored Gold

Mixing gold with different metals changes the color of the gold. For example, mixing copper with gold makes the gold darker yellow, while adding nickel plus zinc or other silver metals produces white gold. Contrary to popular belief, white gold contains no silver, which softens gold and gives it a green tint. Gold alloys also come in colors, including green, red, and blue.

Colored Alloys
Gold Color  Alloys
White 10% to 20% nickel, plus copper, tin, and sometimes platinum or manganese
Green Silver, sometimes cadmium and zinc
Red or Pink Copper
Yellow Silver and copper
Blue Iron
Gold Terminology

When discussing gold’s purity, or what percentage is pure gold, the laws are fairly strict in the U.S. To be labeled as a specific karat, a gold item must be within three parts per thousand of the karat marking for solid pieces and seven parts per thousand for pieces containing solder. Pieces that fail to meet this criterion must be labeled with a lower karat designation. When labeling jewelry and other gold items for sale, you cannot call an item solid gold unless it truly is 24 karat and if you refer to an item as gold, you must designate what karat the gold is.

The term “new gold” does not mean that the gold was recently mined. It means that the gold has been carefully refined to current gold standards. “Old gold,” on the other hand, comes from melting down old jewelry, coins, and other gold items. This old gold may be a slightly lower karat weight than the original gold depending on how much solder was used in the original jewelry pieces. Impurities in old gold pieces cause a variety of headaches during casting, including bubbles, so old gold is often sent for refinement rather than being melted down by your local jeweler and recast into a new item.

Gold solder, which is used to join pieces together, is actually sold based on its color not its gold content. Because the solder needs to have a lower melting point than the pieces it is joining, it is mixed with metals that have lower melting points than gold. The solder is matched to the gold pieces for an attractive look. Though this poses no problems for the owner of the current jewelry item, melting down this piece with its solder in the future will reduce the karat of the gold.

Less Than Solid Gold

With solid gold selling for more than $1,250 per ounce (as of September, 2014), many jewelry makers look for alternative ways of giving their customers the look and feel of gold without the hefty price of solid gold. This is often done by coating pieces made from less expensive metals with thin coats of gold. Items that are made this way are referred to as gold overlay pieces.

When shopping for these pieces there are two distinct methods of overlaying the gold that you need to be aware of. The first is gold filled. Pieces that are gold filled have a minimum of 5% gold applied to the base metal. They are classified based on how much gold is overlayed and the karat of the gold. For example, if a piece is marked 1/20 14K G.F., it means that the piece has a 14 karat gold layer that comprises 1/20 of the weight of the piece. The second type of gold overlay, rolled gold plate, is similar, but the gold can be as thin as 1/40 of the weight. It is also stamped by fineness and content, 1/40 14K RGP. Gold platings are the thinner and less expensive of the two types of gold overlays. The gold is a few thousandths of an inch thick, at best, and wear off easily.

The care of gold overlay pieces is quite different from the care of solid gold pieces because of the fact that the gold is layered on top of another metal. As previously mentioned, the gold on these pieces wears off over time and you cannot use a polishing wheel on these items because it will remove the overlay and potentially ruin the item.

You can learn more about how gold is quoted and priced here.

Silver

With its illustrious history, silver has been more highly valued than gold at various times throughout the years. Long used as a medium of exchange, its name is synonymous with money. Today, silver has found many new uses including photography, batteries, auto glass defogger, and magnetic strips, just to name a few.

Silver’s most outstanding feature is its luster. This Noble Metal is not without its drawbacks though. The main drawback for silver is that it tarnishes. The term tarnish is used to denote a layer of corrosion that forms over some metals, including silver, when they undergo chemical reactions. The chemical reaction that causes silver to tarnish requires a compound called hydrogen sulfide. Silver jewelry encounters hydrogen sulfide in the air you breathe every day, which is why silver tends to tarnish if left out where it is exposed to this compound on a regular basis.

Storing these items in protective pouches or containers where they are exposed to less hydrogen sulfide reduces the amount of tarnish on silver, which means less you can spend less time removing tarnish from your silver jewelry. There are a number of ways to remove tarnish from silver pieces, including silver polish and do-it-yourself methods using common household items, so you do not have to shy away from silver pieces because of the tarnish. Silver jewelry does require more care than some other precious metals, because of the fact that it tarnishes.

Silver is more abundant and much less expensive than gold or platinum, which are additional reasons why it is a popular metal for jewelry; however, it is more difficult to work than gold, because it conducts heat so well. This is why beginning jewelry makers often learn how to solder on silver. Once they gain control of soldering on this highly conductive metal, they find it much easier to control the heat when moving up to gold.

Silver Alloys

Silver is also commonly alloyed with other metals because, like gold, pure silver is soft and easily damaged. Adding harder metals improves the durability of silver, allowing jewelry designers to design pieces that are beautiful and strong enough to wear every day. The most common silver alloy is sterling silver. Sterling silver is 92.5% silver. The remaining 7.5% is comprised of one or more other metals. A substantial portion of this 7.5% is often copper because it increases the hardness of the sterling silver.

The term Mexican silver applies to silver that is used as currency in Mexico and is typically comprised of 95% silver and 5% copper. While the copper increases its durability, it is used more for currency than jewelry. Typically even the silver jewelry made in Mexico is crafted from sterling silver.  You can learn more about silver markings, definitions, and terminology here.

In the U.S., coin silver contains 90% silver and 10% copper. You do not usually see coin silver used in jewelry. Britiannia silver contains a minimum of 95.84% silver, making it a more valuable alloy than sterling. While this may be used in jewelry, it is not common. There are a variety of additional silver alloys used worldwide, including a South American alloy made of 80% silver that does not tarnish. Jewelry makers stamp silver pieces with the code that denotes which alloy of silver it is. For example, 925 is used to designate sterling silver and 958 is used for Britannia silver. When shopping for silver jewelry inspect the piece carefully to determine which alloy was used.

Other Types of Silver Jewelry

While sterling silver is the most common type of silver used in jewelry making, there are some additional alloys that should be mentioned. Electrum, for example, is a naturally occurring alloy of silver and gold that was popular with the ancient Egyptians. Because electrum occurs naturally in nature, the ration of silver to gold varies with each piece.

Niello is a black mixture of silver, copper, and lead. It is used more like an enamel, so you do not typically see jewelry made entirely of niello. It is used as an inlay on etched or engraved metal or to fill in designs. Like electrum, niello was popular with the Egyptians, who used the mixture during the Iron Age.

While all of these silver alloys actually contain at least some silver, some metal names can mislead you into thinking the metal contains silver. Nickel silver or German silver, for example, are alloys of nickel, zinc, and other metals. These metals look like silver, hence the name, but they do not actually contain any silver. The same is true of quicksilver, which is the ancient term given to mercury due to its appearance. While mercury does resemble liquid silver, it does not contain silver and is not seen in jewelry because it is harmful to your health.

Platinum

Platinum is the rarest and most expensive of the Noble Metals. Its unsurpassed holding power and durability make it a highly coveted, premium jewelry metal. Platinum is incredibly durable and does not tarnish, which is why it is often used for engagement and wedding rings.

Though platinum has been found in various objects as far back as 700 BC, its use in jewelry is relatively modern. The main reason for this is that refining platinum proved difficult for a number of centuries because the metal has an extremely high melting point and is highly resistant to corrosion. The oldest recorded use of platinum is as an inlay in ancient Egypt. However, the Egyptians though it was a variation of electrum. Native Americans used platinum in small decorative objects for centuries. Platinum was unknown to Europeans until the Spanish settlers discovered it in Columbia. The Spanish called it platina, meaning little silver, and believed it was unripe gold and, therefore, unusable.

It was not until the eighteenth century that platinum was identified as a new metal and a researcher from Sweden figured out how to melt platinum with arsenic. Once individuals learned how to refine platinum they began to use it to decorate porcelain and to make laboratory equipment. The use of arsenic to refine platinum was extremely dangerous, which is why platinum did not gain popularity until the oxyhydrogen torch was invented in the mid 1800s.

Discoveries of platinum ore in several countries in the nineteenth century brought platinum to the attention of jewelry makers and platinum quickly became a symbol of wealth and celebrity status in the early 1900s. Stars like Greta Garbo and Cole Porter frequently appeared on film with platinum jewelry and accessories. It also became popular for setting exceptional gems. For example, the 530-carat “Star of Africa” diamond in the British royal scepter is set in platinum.

While platinum is still highly coveted in the jewelry industry, it is also used for a variety of industrial purposes. Today, platinum is commonly found in catalytic converters because of its ability to cause chemical reactions while remaining unchanged. In fact, half of the platinum mined in the U.S. and a quarter of the platinum mined worldwide is used for this purpose. The U.S. Bureau of Standards also uses platinum for weights because it never oxidizes and, therefore, remains the same weight forever.

Platinum Alloys

Though most people believe that the term platinum refers to one single type of metal, the truth is it is used to refer to a group of metals that share similar properties. The platinum group includes platinum, iridium, palladium, ruthenium, rhodium, and osmium. Platinum is the most abundant; however, it is not the only one of the group that is used for making jewelry. Rhodium is popular as a non-tarnishing plating for white gold, silver, and other platinum metals. Others from this group, including palladium and iridium, are alloyed with other metals or used alone to make jewelry. In fact, all but osmium are used for jewelry. The most common platinum alloys include 90% platinum and 10% iridium, or 95% platinum and 5% ruthenium. Ruthenium makes for the harder and stronger alloy.

Common Metallurgy Terms

  • Alloy: Mixing two or more metallic elements, especially to give greater strength or resistance to corrosion
  • Amalgamation: Purifying gold by mixing it with mercury.
  • Cementation: To surround a metal with a substance that will react with the metal under heat. Silver is parted from gold by cementation with salt.
  • Cupellation: A means of separating gold and silver from other metals and impurities. The ore is heated in a “cupel,” (a ceramic cup,) which absorbs the impurities.
  • Distillation: Metals with a low boiling point, like mercury, are vaporized to separate them from other metals.
  • Noble Metals: Metals that resists corrosion and oxidation.
  • Smelting: To melt an ore to separate and refine the metals within it.
  • Water Concentration: Washing ore causes the heavier metals to stay behind where they can be recovered.

 

Jewelry Metals 101: Most Commonly Used Jewelry Metals

50 Surprising Facts You Never Knew About Gold

50 Surprising Facts You Never Knew About Gold

1. The word “gold” comes from the Old English word “geolu,” meaning yellow.

2. There is more steel created per hour than there has been gold dug up throughout history.

3. Around 161,000 tons of gold have been mined by humans.

4. Gold can be found beneath the earth on all seven continents.

5. It is believed that around 80% of earth’s gold is still buried underground.

6. There is an estimated total of 10 billion tons of gold in the world’s oceans. That is 25 tons of gold for every cubic mile of seawater.

7. The world’s first gold vending machine was unveiled in May 2010. Located in an ultra-luxury hotel in Abu Dhabi, the vending machine itself is covered in 24-carat gold.

8. Most western economies’ currencies were on the gold standard until 1961.

9. Switzerland was the last country whose currency was tied to gold. 40% of a Swiss Franc was backed by gold until Switzerland joined the IMF in 1999.

 

10. The gold held at Fort Knox is accounted for by the United States as an asset valued at $44.22 per ounce.

11. As of December 31, 1941 Fort Knox held 649.6 million ounces of gold.

12. Today, Fort Knox  holds about 147.3 million ounces.

13. The size of a standard gold bar is 7″ by 3 and 5/8″ by 1 and 3/4″

14. Alchemists believe they can change ordinary materials, such as lead, into gold.

15. A carat was originally a unit of mass based on the carob seed used by ancient merchants.

16. The most expensive gold coin in the world is the 1933 Double Eagle, which was sold at Sotheby’s in New York in 2002 for $7.59 million.

17. Elvis Presley owned three cars manufactured by Stutz Motor Company, in which every part that is normally chrome was converted to gold.

18. Former Tyco International CEO Dennis Kozlowski bought a gold-threaded shower curtain worth $6,000.

19. A noble metal, gold is prone neither to rust nor tarnish and does not form an oxide film on its surface when coming into contact with ai

20. There are 92 naturally occurring elements found in the earth’s crust. Gold ranks 58th in rarity.

21. The chemical symbol for gold is Au, which is derived from the Latin word “aurum,” which means “shining dawn.”

22. Absolutely pure gold is so soft that it can be molded with the hands.

23. The melting point of gold is 2,063 degrees Fahrenheit.

24. Gold is a great conductor of electricity.

25. Gold is the most malleable and ductile pure metal known to man.

26. An ounce of gold can be beaten into a sheet covering 100 square feet.

27. In 1869, two Australians unearthed the world’s largest nugget of gold, the “Welcome Stranger,” which measured 10 by 25 inches before it was melted down.

28. The largest nugget still in existence is the “Hand of Faith,” found in 1980 in Australia. It is currently on display at the Golden Nugget Casino in Las Vegas.

29. A gold nugget found in the earth can be three to four times as valuable as the gold it contains because of its rareness.

30. The heaviest modern gold bullion coin is Austria’s Philharmonic. In 2004, the coin, which has a weight of 1,000 ounces (31.1 kilograms or 69 troy pounds or 828 troy ounces) and a diameter of 15 inches, was dubbed the world’s largest gold coin by Guinness World Records.

31. In 2007, Canada made a 100 kilogram (3,217 troy ounce), 0.99999 gold coin with a face value of $1,000,000.

32. Pure gold does not cause skin irritations.

33. Some sufferers of rheumatoid arthritis receive injections of liquid gold to relieve pain.

34. Olympic gold medals were pure gold until 1912.

35. An ounce of gold can be drawn into a wire 60 miles long.

36. Two thirds of the world’s gold comes from South Africa.

37. India is the world’s largest consumer of gold today.

38. South Asian jewelry is generally more pure than western jewelry, comprised of 22 carat gold rather than 14 carat.

39. Gold is the state mineral of California and Alaska.

#-ad_banner_2-#40. 90% of the world’s gold mining has been done since the discovery of gold at Sutter’s Mill in California in 1848.

41. During the California gold rush, some speculators paid more for an ounce of water than they received for an ounce of gold.

42. South Dakota and Nevada produce more gold than any other states.

43. Scientists believe that gold can be found on Mars, Mercury, and Venus.

44. The visors of astronauts’ helmets are coated in a very thin, transparent layer of gold (.000002 inches) that reduces glare and heat from sunlight.

45. The Aztec word for gold, “teocuitatl,” was translated by Europeans as meaning “excrement of the gods.”

46. According to the legend of El Dorado (the gilded one), an Andean chief who was covered in gold dust would make offerings of gold into a mountain lake.

47. Evidence suggests that around 5,000 B.C., gold and copper became the first metals to be discovered by man.

48. King Croesus of Lydia created the first pure gold coins in 540 B.C.

49. When Franklin Roosevelt raised the price of gold from $20.67 to $35 in 1934, the dollar immediately lost 40% of its value.

50. Henry VIII, Diocletian and Nero were infamous gold debasers, mixing other metals into gold coins and decreasing their value.

http://www.investinganswers.com/investment-ideas/commodities-precious-metals/50-surprising-facts-you-never-knew-about-gold-1370

Precious Metals….did you know??????

Precious metals

Gold, silver, and platinum have historically been valued for their beauty and rarity. They are the precious metals . Platinum usually costs slightly more than gold, and both metals are about 80 times more costly than silver. Precious metal weights are given in Troy ounces (named for Troyes, France, known for its fairs during the Middle Ages) a unit approximately 10% larger than 1 oz (28.35 g).

The ancients considered gold and silver to be of noble birth compared to the more abundant metals. Chemists have retained the term noble to indicate the resistance these metals have to corrosion , and their natural reluctance to combine with other elements.

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The legends of King Midas and Jason’s search for the golden fleece hint at prehistoric mankind’s early fascination with precious metals. The proof comes in the gold and silver treasure found in ancient Egyptian tombs and even older Mesopotamian burial sites.

The course of recorded history also shows twists and turns influenced to a large degree by precious metals. It was Greek silver that gave Athens its Golden Age, Spanish gold and silver that powered the Roman Empire‘s expansion, and the desire for gold that motivated Columbus to sail west across the Atlantic. The exploration of Latin America was driven in large part by the search for gold, and the Jamestown settlers in North America had barely gotten their “land legs” before they began searching for gold. Small amounts of gold found in North Carolina, Georgia, and Alabama played a role in the 1838 decision to remove the Cherokee Indians to Oklahoma. The California gold rush of 1849 made California a state in 1850, and California gold fueled northern industry and backed up union currency, two major factors in the outcome of the Civil War.

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Since ancient times, gold has been associated with the Sun . Its name is believed to be derived from a Sanskrit word meaning “to shine,” and its chemical symbol (Au) comes from aurum, Latin for “glowing dawn.” Pure gold has an attractive, deep yellow color and a specific gravity of 19.3. Gold is soft enough to scratch with a fingernail, and the most malleable of metals. A block of gold about the size of a sugar cube can be beaten into a translucent film some 27 ft (8 m) on a side. Gold’s purity is expressed either as fineness (parts per 1,000) or in karats (parts per 24). An alloy containing 50% gold is 500 fine or 12 karat gold. Gold resists corrosion by air and most chemicals but can be dissolved in a mixture of nitric and hydrochloric acids, a solution called aqua regia because it dissolves the “king of metals”.

Gold is so rare that one ton of average rock contains only about eight pennies worth of gold. Gold ore occurs where geologic processes have concentrated gold to at least 250 times the value found in average rock. At that concentration, there is still one million times more rock than gold and the gold is rarely seen. Ore with visible gold is fabulously rich.

Gold most commonly occurs as a pure metal called native gold or as a natural alloy with silver called electrum. Gold and silver combined with tellurium are of local importance. Gold and silver tellurides are found, for example, in the mountains around the old mining boom-town of Telluride, Colorado. Gold is found in a wide variety of geologic settings, but placer gold and gold veins are the most economically important.

Placer gold is derived from gold-bearing rock from which the metal has been freed by weathering . Gravity and running water then combine to separate the dense grains of gold from the much lighter rock fragments. Rich concentrations of gold can develop above deeply weathered gold veins as the lighter rock is washed away. The “Welcome Stranger” from the gold fields of Victoria, Australia , is a spectacular 158–16 (71.5-kg) example of this type of occurrence.

Gold washed into mountain streams also forms placer deposits where the stream’s velocity diminishes enough to deposit gold. Stream placers form behind boulders and other obstructions in the streambed, and where a tributary stream merges with a more slowly moving river. Placer gold is also found in gravel bars where it is deposited along with much larger rocky fragments.

The discovery of placer gold set off the California gold rush of 1849 and the rush to the Klondike in 1897. The largest river placers known are in Siberia, Russia. Gold-rich sands there are removed with jets of water, a process known as hydraulic mining. A fascinating byproduct of Russia’s hydraulic mining is the unearthing of thousands of woolly mammoths, many with flesh intact, locked since the Ice Age in frozen tundra gravel.

Stream placer deposits have their giant ancient counterparts in paleoplacers, and the Witwatersrand district in South Africa outproduces all others combined. Gold was reported from the Witwatersrand (White Waters Ridge) as early as 1834, but it was not until 1886 that the main deposit was discovered. From that time until today, it has occupied the paramount position in gold mining history. Witwatersrand gold was deposited between 2.9 and 2.6 billion years ago in six major fields, each produced by an ancient river system.

Placer and paleoplacers are actually secondary gold deposits, their gold having been derived from older deposits in the mountains above. The California 49ers looked upstream hoping to find the mother lode, and that’s exactly what they called the system of gold veins they discovered.

Vein gold is deposited by hot subterranean water known as a hydrothermal fluid. Hydrothermal fluids circulate through rock to leach small amounts of gold from large volumes of rock and then deposit it in fractures to form veins. Major U.S. gold vein deposits have been discovered at Lead in the Black Hills of South Dakota and at Cripple Creek on the slopes of Pike’s Peak, Colorado. Important vein deposits are also found in Canada and Australia. All these important deposits were located following the discovery of placer gold in nearby streams.

Gold’s virtual indestructibility means that almost all gold ever mined could still be in use today. Today, gold is being mined in ever-increasing amounts from increasingly lower-grade deposits. It is estimated that 70% of all gold recovered has been mined in this century. Each year nearly 2,000 tons are added to the total. Nevada currently leads the nation in gold production, and the Republic of South Africa is the world’s leading gold-producing nation.

Gold has traditionally been used for coinage, bullion, jewelry, and other decorative uses. Gold’s chemical inertness means that gold jewelry is hypoallergenic and remains tarnish-free indefinitely.

Silver is a brilliant white metal and the best metal in terms of thermal and electrical conductivity. Its chemical symbol, Ag, is derived from its Latin name, argentum, meaning “shining white.” Silver is not nearly as precious, dense, or noble as gold or platinum. The ease with which silverware tarnishes is an example of its chemical reactivity. Although native silver is found in nature, it most commonly occurs as compounds with other elements, especially sulfur.

Hydrothermal veins constitute the most important source of silver. The Comstock Lode, a silver bonanza 15 mi (24 km) southeast of Reno, Nevada, is a well-known example. Hydrothermal silver veins are formed in the same manner as gold veins, and the two metals commonly occur together. Silver, however, being more reactive than gold, can be leached from surface rocks and carried downward in solution. This process, called supergene enrichment, can concentrate silver into exceedingly rich deposits at depth.

Mexico has traditionally been the world’s leading silver producing country, but the United States, Canada, and Peru each contribute significant amounts. Although silver has historically been considered a precious metal, industrial uses now predominate. Significant quantities are still used in jewelry, silver ware, and coinage; but even larger amounts are consumed by the photographic and electronics industries.

Platinum, like silver, is a silver-white metal. Its chemical symbol is Pt and its name comes from the Spanish world for silver (plata ), with which it was originally confused. Its specific gravity of 21.45 exceeds that of gold, and, like gold, it is found in pure metallic chunks in stream placers. The average crustal abundance of platinum is comparable to that of gold. The melting point of platinum is 3,219°F (1,769°C), unusually high for a metal, and platinum is chemically inert even at high temperature . In addition, platinum is a catalyst for chemical reactions that produce a wide range of important commodities.

Platinum commonly occurs with five similar metals known as the platinum group metals. The group includes osmium, iridium, rhodium, palladium, and ruthenium. All were discovered in the residue left when platinum ore was dissolved in aqua regia. All are rare, expensive, and classified chemically as noble metals.

Platinum is found as native metal, in natural alloys, and in compounds with sulfur and arsenic. Platinum ore deposits are rare, highly scattered, and one deposit dominates all others much as South Africa’s Witwatersrand dominates world gold production. That platinum deposit is also in the Republic of South Africa.

Placer platinum was discovered in South Africa in 1924 and subsequently traced to a distinctively layered igneous rock known as the Bushveld Complex. Although the complex is enormous, the bulk of the platinum is found in a thin layer scarcely more than three feet thick. Nearly half of the world’s historic production of platinum has come from this remarkable layer.

The Stillwater complex in the Beartooth mountains of southwestern Montana also contains a layer rich in platinum group metals. Palladium is the layer’s dominant metal, but platinum is also found. The layer was discovered during the 1970s, and production commenced in 1987.

Platinum is used mostly in catalytic converters for vehicular pollution control. Low-voltage electrical contracts form the second most common use for platinum, followed closely by dental and medical applications, including dental crowns, and a variety of pins and plates used internally to secure human bones. Platinum is also used as a catalyst in the manufacture of explosives, fertilizer, gasoline, insecticides, paint, plastics, and pharmaceuticals. Platinum crucibles are used to melt high-quality optical glass and to grow crystals for computer chips and lasers. Hot glass fibers for insulation and nylon fibers for textiles are extruded through platinum sieves.

Because of their rarity and unique properties, the demand for gold and platinum are expected to continue to increase. Silver is more closely tied to industry, and the demand for silver is expected to rise and fall with economic conditions.

 

http://www.encyclopedia.com/earth-and-environment/minerals-mining-and-metallurgy/metallurgy-and-mining-terms-and-concepts-47