One of the world’s most beautiful and exotic islands, Sri Lanka, (formerly Ceylon) lies just below the southern tip of India. This pear-shaped bit of tropical paradise, about the size of Sicily, is a tourist’s delight offering British teahouses, rubber plantations, and gem mines.Marco Polo wrote of his visit in 1292: “I want you to understand that the island of Ceylon is, for its size, the finest island in the world, and from its streams comes rubies, sapphires, topazes, amethyst and garnet.” Little has changed since Marco Polo’s time except that Sri Lanka faces overpopulation and a faltering economy.Its gemstones, however, seem to occur in endless supply. Known as the “Jewel Box of the Indian Ocean,” Sri Lanka, like possibly no other locality on earth, has yielded precious stones and fine gems in a great profusion of gem species and varieties.
The island was known in the ancient world as Taprobane (copper colored in Greek). Native Veddahs, bathing in smooth flowing streams, noticed colored pebbles scattered in sandy bottoms. It was not until 500 B.C. that conquering Buddhists from northern India also discovered gems in the rivers and began to set rough stones into crude jewelry. They bartered stones with traders from abroad and eventually the treasures found their way to the marketplaces of Asia and Europe. Ancient Greek and Chinese historians referred to the beautiful gems of Ceylon, and King Solomon reportedly wooed the Queen of Sheba with Ceylonese precious stones.
Geologically, gemstones originated within a broad belt known as the Highland Series which runs through the center of Sri Lanka. The edges of the belt form a trough bordered by chains of mountains and peaks. The trough, made up of highly crystalline Precambrian metamorphosed rock, featured components of schists, quartzite, marbles, and sometimes pegmatite deposits. Rock erosion resulted in the formation of extensive gem-laden placer deposits along stream beds in lower valleys.
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Mineral:Corundum
var. Sapphire
Locality: Central
Highland Belt, near Ratnapura, Sri Lanka (Ceylon)
Description: Doubly-terminated
crystal of blue sapphire variety of corundum.
Overall Size:14x4x3
mm
Crystals:14
mm
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Miners soon learned the richest deposits were composed of blue and yellow clays called illam which lay just below the surface of lush valley farmlands. During their tortuous journey downstream, most gem crystals were worn to rounded pebbles, but harder than host minerals, they managed to retain much of their size.Every available square meter of stream bed was mined until all known gem areas were exhausted. The miners discovered that the rivers they were working were in reality “surface streams” and that by digging downward from 7 to 30 meters, “ancient streams” could be encountered. Unfortunately most of the ancient streams lay beneath cultivated fields. Prospecting and mining operations caused great destruction to crops and created considerable animosity between farmer and miner.
Eventually new mining methods were devised whereby the gem hunter could operate at a profit and still leave the farmland virtually intact. A vertical shaft was dug downward until the illam was reached. Feeder tunnels extended in a number of directions like the spokes on a wheel. The shaft and tunnels were carefully supported by wood and bamboo timbers. The miners dug along the tunnels, loaded the gravel into knapsacks, and then climbed to the surface with their loads.
Washing, screening, and sorting occurred on the surface. Usually pumps operated full time to keep the tunnels free of water. When a mine played out, the tunnels were closed off, the shaft filled, the buildings removed, and new topsoil spread over the area. As another growing season approached, all vestiges of the mine vanished.
Ratnapura (Singhalese for ‘gem town’) lies about 100 kilometers southeast of Colombo. Its mining region has produced an incredible variety of gemstones, many of them outstanding in comparison with stones from other regions. Sapphire occurs in all hues of blue, as well as yellow, violet, green, pink, and the remarkable pinkish-orange “padparadsha.” Other gemstones include topaz in bright yellow with a reddish tinge; brownish yellow to cinnamon-colored grossular; orange-yellow spessartine; blood-red pyrope; red to brownish red almandine; the world’s finest zircon in a broad spectrum including brown, yellow, orange, green, and colorless (known locally as ‘Matara diamond’—a misnomer); green, yellow, and brown tourmaline; yellow, green, and brown chrysoberyl; yellow chrysoberyl cat’s-eye; the unique white translucent variety of microcline with a blue sheen known as moonstone; and great quantities of spinel in brown, green, blue, purple, violet, yellow, pink, and red. Unusual and rare stones from the same area include sillimanite, andalusite, scapolite, enstatite, kornerupine, diopside, and sinhalite. Recently a 5000-carat cat’s-eye chrysoberyl, the size of a man’s fist, was taken from a mine near Ratnapura.
The crown jewels of many monarchs gleam with extraordinary spinels, sapphires, and zircons mined from Sri Lanka streams. The Imperial Treasury of the Soviet Union houses a 400-carat red spinel of great beauty which was once given to Catherine the Great. The British Imperial Crown features a giant oval-cut spinel (previously supposed to be a ruby), known as the “Black Prince.” Crowns in the Green Vaults of Dresden are covered with sapphires from Sri Lanka.
Sri Lanka gem producing areas are 5 in number . The traditional areas extend from Avissawella, to Balangoda to Embilipitiya. This area includes the most important mining centers Eheliyagoda, Ratnapura, Pelmedulla and Kahawatte.
Local lapidaries cut most of the island’s gem rough. Striving for maximum weight in each finished stone, cutters frequently align the faces poorly with the center of the stone. Therefore, many stones must be recut, causing a weight loss, before reaching their full potential.
Gem Mining Steps Most gem mines are found in thick jungles where facilities like electricity and such are not available. Logs of rubber trees are very important in gem mining.These logs are transported manually. Rubber logs are used exclusively to strengthen the four walls of the mine.Once obtained, they are cut into square blocks of specific sizes so they can absorb large volumes of water.
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| Gem pit |
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| Manually operated roller |
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| Going down to gem shaft |
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| View from bottom to top |
After preparing the rubber logs and the location for the gem pit has been identified and the boundaries demarcated the clearing of the site is started. Now the digging of the gem pit commences after invoking the blessings of the gods.
Once the pit is dug deep, the implements have to be supplied to miners and arrangements have to be made to take the soil out.For this purpose, a manually operated roller is used to transport implements and other materials down and to bring the soil to the surface.Once the digging progresses, the pit gets filled with water which has to be constantly pumped out.for this purpose a fuel operated,high powered water-pump is used.
Communication from those inside the mine to those above is vital.The only source of light inside the mines are from candles. Candles also act as a warning of dangers from harmful gases, as the candles will not light if there is such a gas.
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| Working with Candle light |
Once the gem bearing gravels are found inside the cross tunnels, this gravel is broken with the help of a crow-bar.
Sending up this gem bearing gravel to the top is a time consuming exercise.They are filled into a basket and set up through a roller- operated rope.The piled up gravel is collected and carefully piled up near the mine until all the gravel is unearthed.The water pumped out of the mines, now comes in handy as it is used to wash the gravel.Gravel in baskets is washed in a deep water pit.
Washing of the gravel is a job of an expert as you may see with every hulling the lighter stones come to the top and the heavier ones descend to the bottom and settle there.
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| illam is washed in a deep water pit |
The gods, whose blessings were evoked at the beginning of the operation are now thanked for the blessings and help given.
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| Recovering gems from rattan basket |
Prince William and Kate Middleton Wedding Ring
One of the highlights of any royal wedding is the jewelry, especially the wedding and engagement rings exchanged by the couple. Prince William gifted a large blue sapphire ring to Kate Middleton, the large sapphire was originally mined in Sri Lanka and now weighs 18 carats. Sri Lankan sapphires also known as Ceylon sapphires, have always held an important position in the global gems and jewelry industry. Sapphires are rare gems and belong to the corrundum group of minerals. A big sapphire gemstone would be one where the gem size is around 3 carats or more. With this definition the 18 carat blue sapphire in the ring worn by Kate, is exceptionally large.
A Sri Lankan Gem and Jewellers organization, claims that the big blue sapphire worn by Kate Middleton for the wedding was mined in Sri Lanka. A mine located in the central portion of the country, was where the big sapphire was mined. The stone was apparently sold around 35 years ago.
Some parts of his article are extracted from Dr. Peter Bancroft’s classic book, Gem and Crystal Treasures (1984)
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ReplyDeletewhat is the english name for rathu kataya ??
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