Pearls – The Birthstone of June – Part 7

History

Pearl hunting

A 14th-century piece of clothing used by Kuwaiti divers searching for pearls in the Persian Gulf

The ancient chronicle Mahavamsa mentions the thriving pearl industry in the port of Oruwella in the Gulf of Mannar in Sri Lanka. It also records that eight varieties of pearls accompanied Prince Vijaya’s embassy to the Pandyan king as well as king Devanampiya Tissa’s embassy to Emperor Ashoka.  Pliny the Elder (23–79AD) praised the pearl fishery of the Gulf as most productive in the world.

For thousands of years, seawater pearls were retrieved by divers in the Indian Ocean in areas such as the Persian Gulf, the Red Sea and the Gulf of Mannar. Evidence also suggest a prehistoric origin to pearl diving in these regions. Starting in the Han Dynasty (206 BC–220 AD), the Chinese hunted extensively for seawater pearls in the South China Sea. Tanka pearl divers of twelfth century China attached ropes to their waists in order to be safely brought back up to the surface.

When Spanish conquistadors arrived in the Western Hemisphere, they discovered that around the islands of Cubagua and Margarita, some 200 km north of the Venezuelan coast, was an extensive pearl bed (a bed of pearl oysters). One discovered and named pearl, La Peregrina pearl, was offered to Philip II of Spain and then gifted to his wife Mary I of England. According to Garcilasso de la Vega, who says that he saw La Peregrina at Seville in 1607, this was found at Panama in 1560 by a slave worker who was rewarded with his liberty, and his owner with the office of alcalde of Panama.

Margarita pearls are extremely difficult to find today and are known for their unique yellowish color. The most famous Margarita necklace that anyone can see today is the one that then Venezuelan President Romulo Betancourt gave to Jacqueline Kennedy when she and her husband, President John F. Kennedy paid an official visit to Venezuela.

Before the beginning of the 20th century, pearl hunting was the most common way of harvesting pearls. Divers manually pulled oysters from ocean floors and river bottoms and checked them individually for pearls. Not all mussels and oysters produce pearls. In a haul of three tons, only three or four oysters will produce perfect pearls.

British Isles

Pearls were one of the attractions which drew Julius Caesar to Britain. They are, for the most part, freshwater pearls from mussels. Pearling was banned in the U.K. in 1998 due to the endangered status of river mussels. Discovery and publicity about the sale for a substantial sum of the Abernethy pearl in the River Tay had resulted in heavy exploitation of mussel colonies during the 1970s and 80s by weekend warriors. When it was permitted it was carried on mainly by Scottish Travellers who found pearls varied from river to river with the River Oykel in the Highlands being noted for the finest rose-pink pearls. There are two firms in Scotland that are licensed to sell pre-1998 freshwater pearls.

Pearl farming

A pearl being extracted from an akoya pearl oyster. See also: Oyster farming

Today, the cultured pearls on the market can be divided into two categories. The first category covers the beaded cultured pearls, including akoya, South Sea and Tahiti. These pearls are gonad grown, and usually one pearl is grown at a time. This limits the number of pearls at a harvest period. The pearls are usually harvested after one year for akoya, 2–4 years for Tahitian and South Sea, and 2–7 years for freshwater. This perliculture process was first developed by the British biologist William Saville-Kent who passed the information along to Tatsuhei Mise and Tokichi Nishikawa from Japan. The second category includes the non-beaded freshwater cultured pearls, like the Biwa or Chinese pearls. As they grow in the mantle, where on each wing up to 25 grafts can be implanted, these pearls are much more frequent and saturate the market completely. An impressive improvement in quality has taken place in the last ten years when the former rice-grain-shaped pebbles are compared with the near round pearls of today. In the last two years large near perfect round bead nucleated pearls up to 15mm in diameter have been produced with metallic luster.

The nucleus bead in a beaded cultured pearl is generally a polished sphere made from freshwater mussel shell. Along with a small piece of mantle tissue from another mollusk (donor shell) to serve as a catalyst for the pearl sac, it is surgically implanted into the gonad (reproductive organ) of a saltwater mollusk. In freshwater perliculture, only the piece of tissue is used in most cases, and is inserted into the fleshy mantle of the host mussel. South Sea and Tahitian pearl oysters, also known as Pinctada maxima and Pinctada margaritifera, which survive the subsequent surgery to remove the finished pearl, are often implanted with a new, larger beads as part of the same procedure and then returned to the water for another 2–3 years of growth.

Despite the common misperception, Mikimoto did not discover the process of pearl culture. The accepted process of pearl culture was developed by the British Biologist William Saville-Kent in Australia and brought to Japan by Tokichi Nishikawa and Tatsuhei Mise. Nishikawa was granted the patent in 1916, and married the daughter of Mikimoto. Mikimoto was able to use Nishikawa’s technology. After the patent was granted in 1916, the technology was immediately commercially applied to akoya pearl oysters in Japan in 1916. Mise’s brother was the first to produce a commercial crop of pearls in the akoya oyster. Mitsubishi’s Baron Iwasaki immediately applied the technology to the south sea pearl oyster in 1917 in the Philippines, and later in Buton, and Palau. Mitsubishi was the first to produce a cultured south sea pearl – although it was not until 1928 that the first small commercial crop of pearls was successfully produced.

The original Japanese cultured pearls, known as akoya pearls, are produced by a species of small pearl oyster, Pinctada fucata martensii, which is no bigger than 6 to 8 cm (2.4 to 3.1 in) in size, hence akoya pearls larger than 10 mm in diameter are extremely rare and highly priced. Today, a hybrid mollusk is used in both Japan and China in the production of akoya pearls.

Cultured Pearls were sold in cans for the export market. These were packed in Japan by the I.C.P. Canning Factory (International Pearl Company L.T.D.) in Nagasaki Pref. Japan.

(Information from Wikipedia, the free encyclopedia)