How Were Birthstones Chosen for Each Month?

How Were Birthstones Chosen for Each Month?

Photos of Birthstones

Do you have a favorite type of gemstone? Of course, many people love diamonds. But there are many other types of beautiful gemstones.

In fact, each month of the year has a particular gemstone associated with it. We call these special monthly gemstones birthstones, since many people believe the particular gemstone that corresponds to the month of their birth has special properties.

How did certain gemstones become associated with the months of the year? Experts believe that birthstones can be traced back to the Bible. In Exodus 28, Moses sets forth directions for making special garments for Aaron, the High Priest of the Hebrews. Specifically, the breastplate was to contain twelve precious gemstones, representing the twelve tribes of Israel.

Later, these twelve stones were likely also linked to the twelve signs of the zodiac. Eventually, they also became associated with the twelve months of the calendar year.

Throughout history, there have been many myths and legends associated with birthstones. Many cultures have believed that birthstones have magical healing powers or bring good luck. Not all cultures have agreed on which stones correspond to which months, though, so you can find different lists of birthstones over the course of time.

Today, most jewelers agree on a basic set of birthstones. Let’s take a look through the calendar to learn a bit more about each of these birthstones.

The birthstone for the month of January is the garnet. Some believe garnets provide safety during travels. February’s birthstone is the amethyst, which is thought to make one courageous. If your birthday is in March, your birthstone is the aquamarine. Aquamarines have been associated with certain healing powers.

April features what is arguably the most coveted birthstone: the diamond. Diamonds remain an enduring symbol of love. Another birthstone associated with love is the emerald, which is the birthstone of May. June’s birthstone is another popular jewel: the pearl. Pearls have long been a symbol of purity.

The birthstone for July is the ruby. Ancient cultures believed the ruby could ward off evil. The peridot is the birthstone of August. Symbolizing strength, the peridot is sometimes known as the “evening emerald” due to its light green color. September’s birthstone, the sapphire, was also thought to guard against evil, especially poisoning.

The opal is the birthstone of October. It represents faithfulness and confidence. November’s birthstone, the topaz, is usually associated with love and affection. Finally, December’s birthstone is the turquoise, which was often thought to symbolize luck and success.

 

https://wonderopolis.org/wonder/how-were-birthstones-chosen-for-each-month

Diamond basic attributes – the 4Cs

Diamond basic attributes – the 4Cs

4C represents Color, Clarity, Cutting and Carat. The 4Cs are the shared common attributes used by different grading institutes, to determine the quality and value of each diamond. Therefore, it is crucial to know the 4Cs before buying a diamond.

1) Carat

Carat is the weighting unit of a diamond, as below:
1 carat = 0.2 grams = 0.007 oz.

Bigger diamonds are rarer, as such, the value per carat will also be higher. For example, the value of a 1 carat diamond would be much higher than the total of two 0.5 carat diamonds.

The weight of a diamond affects its size, although the same weight may lead to different sizes, the following table shows the approximate size to weight ratio:

2) Clarity

Diamond with no magnificationDiamond at 10x magnification

Clarity refers to the inclusion and blemishes of a diamond; the level of clarity is determined by the number, size, place, whether it is obvious and the general effect of those inclusions and blemishes to the appearance of a diamond. Since diamonds are formed naturally, the formation process would usually include some other substances which lead to so called crystals, feathers inside a diamond. Better clarity gives a higher value of a diamond.

The GIA Clarity Scale contains 11 grades. In determining a clarity grade, the GIA system considers the size, nature, position, color or relief, and quantity of clarity characteristics visible under 10× magnification.

 

Flawless (FL) – No inclusions or blemishes are visible to a skilled grader using 10× magnification

Internally Flawless (IF) – No inclusions and only blemishes are visible to a skilled grader using 10× magnification

Very, Very Slightly Included (VVS1 and VVS2) – Inclusions are difficult for a skilled grader to see under 10× magnification

Very Slightly Included (VS1 and VS2) – Inclusions are minor and range from difficult to somewhat easy for a skilled grader to see under 10x magnification

Slightly Included (SI1 and SI2) – Inclusions are noticeable to a skilled grader under 10x magnification

Included (I1, I2, and I3) – Inclusions are obvious under 10× magnification and may affect transparency and brilliance

 

Since the diamond with “Included” grading includes quite obvious inclusion, we do not recommend and also do not offer diamonds with Grade I1 , I2 & I3 , except customers request us to provide.

3) Color

It refers to the level of colorless of a diamond. The rating is from D to Z. For D color, the best color level, representing colorless and continues with increasing presence of color to the letter Z, or light yellow or brown, as shown below:

D E F G H I J K L M N O P Q R S T U V W X Y Z
COLORLESS NEAR COLORLESS FAINT YELLOW VERY LIGHT YELLOW LIGHT YELLOW

 

Many of these color distinctions are so subtle as to be invisible to the untrained eye. But these slight differences make a very big difference in diamond quality and price.

4) Cutting

Color and clarity are born naturally with a diamond; however, on the other hand, Cutting is determined by the craftsmanship the diamond receives, which is an important factor to lead the diamond to sparkling perfection. The cutting factor involves complex determination, as a value factor, though, it refers to a diamond’s proportions, symmetry and polish.

Too Shallow Ideal Cut Too Deep

The proportions of a diamond refer to the relationships between table size, crown angle and pavilion depth. A wide range of proportion combinations are possible, and these ultimately affect the stone’s interaction with light.

GIA diamond graded cutting into 5 categories, from Excellent to Poor.

 

http://www.sydiamond.com/diamond_knowledge_tips_e.php

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

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

Lost Money: $41 Billion In Gift Cards Haven’t Been Redeemed Since 2005

Lost Money: $41 Billion In Gift Cards Haven’t Been Redeemed Since 2005

A gift card display at a Target store in Mayfield Hts., Ohio., last month.

Amy Sancetta/AP

You may have given one — or two, or three. You may have gotten one — or two, or three.

Gift cards.

Now you may be wondering what to do with them (more on that in moment).

They’re the presents that show up in Christmas stockings all across America. The go-to gifts for aunts and uncles trying to please those finicky teenaged nieces and nephews. The tokens of affection that may say “I got this on the way over here.”

And, also, the gifts that sometimes never get used.

Since 2005, analyst Brian Riley of the TowerGroup research firm estimates, about $41 billion worth of the money on gift cards has gone unclaimed. That’s such a huge figure it was Saturday’s “number of the week” at The Wall Street Journal‘s Real Time Economics blog.

So how do you avoid falling into that trap?

The simple answer, of course, is to go out and use that card. Hopefully, it’s one that can be applied to things you like or need.

But let’s say it’s a card you don’t think you’ll ever use.

Forbes says one way to get around the problem is by reselling. Plastic Jungle, it reports, is among the online outfits that will pay 80 percent or more of many cards’ face values.

The Journal points to that site two others that buy cards: GiftCardRescue.com and CardPool.com.

Or, says MarketWatch.com’s Consumer Confidential column, there’s also a way to invest the money on a card: “GoalMine.com is an investment site that allows you to invest in a mutual fund for as little as $25 (the total expense ratios for the funds you can purchase through GoalMine currently are about 1.12% to 1.4%). Through January you can trade the market value of a gift card, as determined by its partner PlasticJungle, to your GoalMine account. As a bonus, GoalMine will redeem your first gift card for 150% of its value, which is applied to a GoalMine mutual fund or savings account.”

Of course, you could also do some “regifting” — pass that card along to someone else in the family who has a birthday coming up. Kind of cheesy, but an option.

Or, there’s always the altruistic route: Donate the card or an amount left on it to a charity. Call your favorite to see if it will take the card.

Other ideas? Please share them in the comments thread.

Paul Brown and Mark Memmott on the NPR Newscast

By the way, the National Retail Federation estimates that $27.8 billion worth of gift cards have been given this holiday season.

Update at 11:45 a.m. ET. A Bit More On The Accounting Rules:

In general, as USA Today says, “retailers can’t count gift card sales as income until they are redeemed.”

So when can a company declare its revenue from unused gift-cards as income?

The Journal says there “are no hard-and-fast rules. … The Securities and Exchange Commission allows companies to take unused gift-card money as income once they can reasonably say the card won’t be redeemed, but there’s no set time limit. Best Buy, for example, sets that level at about two years. … But some states don’t allow companies to keep unused gift-card cash. They demand that companies give the money to the state after a certain period of time to add to unclaimed-funds accounts.”

According to the Journal, in 2008 the state of New York “collected $9.6 million in unredeemed gift cards and returned around $2,150 to the rightful owners.”

 

http://www.npr.org/sections/thetwo-way/2011/12/27/144308234/lost-money-41-billion-in-gift-cards-havent-been-redeemed-since-2005

“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