Pre-historic evidences prove that Sri Lanka has been famously celebrated for priceless gems since the days gone by. The antiquity of gem industry in Sri Lanka, which is called “Rathnadveepa” and “Serandib”, is evidenced in a recently found Brahmi epigraph that belongs to third century B.C., which mentions “Minikara” (lapidary) in its content. Sinhala chronicles like “Maha Wanshaya” and “Choola Wanshaya” also bespeak words like “Ruwanmini” signifying the availability of precious stones in the country. Gem thus has held the most outstanding place among valuables since the days of yore. Historical details reveal about a conflict occurred between two kings of the tribe called “Na” named “Chullodara” and “Mahodara” for a bejeweled throne. In the stories of Sinbad Seaman, Sri Lanka is indicated as “Menik Nimnaya” (valley of jewels), and details about Lankan gem is documented in Chinese and Greek scripts. Foreign tourists like Marco Polo, Iban Batuta, and Pahiyan have recorded important documents about Ceylon gem with the intention of winning the love of queen Sheba. Considering the whole picture, it is crystal clear that Sri Lanka has been internationally renowned for gems at least about one thousand years ago. Similarly, since ancient times, Ratnapura has been famous for gem mining. The District, which is named after the meaning “Gem City” (Ratnapura), has extensive annals. Ratnapura, Kuruvita, Pelmadulla, Rakwana, Nivithigala, Kalawana, Rambuka, Eheliyagoda, Kiriella, Ayagama and Balangoda can be mentioned as the most gem copious areas and Mathara, Mathale, Polonnaruwa, Galle, Kaluthara and Nuwaraeliya Districts are also designated as some other places host in gem.
As Ratnapura District comes prior to all of these areas its worthy to mention the configuration of gem under the earth of this area. Gems that are vastly accumulated in the sole of all the rivers that stream across Ratnapura District lie deeper than about 32 m into the earth from surface. The value of gem stones which are subsided until the anterior basal named “Malawa” is evaluated considering weight and hardness. A greater deal and a hard effort must be afforded to dig and treasure out the precious gems from deep within the interior basal to the surface. A traditional vocabulary, which has been woven around the mining industry, can also be untwisted. A multitude of lexis and idioms like “Pathal Kepime” (digging out mines), “Menik Gereema” (gemming), “Menik Veladama” (trading gem) and lapidary skills could be found in the diction related to gem industry. A hard role with strenuous exertion or a hard endeavor must be played in gemming. The process of gemming in lands can be categorized into two as ‘open cast mine’ and ‘deep tunnel mines’. According to the configuration of land where mining is to be done the measure of the mine varies from 4×4 cubits to 8×8 cubits. If earth is so hard and inflexible 4×4 cubits mine is better. Otherwise the 8×8 cubits’ mine is as usual as a fixed custom in mining. Caoutchouc (rubber) timber and areca fibers are used to strengthen the walls of a mine. Lathe part of rubber timbers would measure about 6×6 inches wide and areca fibers would measure only about 2 inches wide. This kind of panning is done only in opencast mines, although mining is done in brooks and rivers also. They are called dragline mines. The foremost tool used in a dragline mine is drag-hoe. The blade of it is about 2 or 2½ ft. long and 1 ft. wide. A 15-20 ft. long rod is fixed to the blade as a handle. Raddles should be erected to turn the flow of water as it runs near the dragline mine. Fleetness of water is adjusted in the stead named “Hiti Adiya”, a place arranged simply to collected sand. Likewise, all the sand which is dragged using drag-hoe is collected and washed in “Hiti Adiya”. When the vein of gem emerged, that is also placed in Hiti Adiya. In it gem stones remain as they are heavier, while oddments are washed out. Gems, which are mined out from earth using various techniques likewise, are sold in various ways and means advance. Gradating, selecting, and assessing the value of gem are done according to the solidity of gem-stone.
To come to a précis conclusion about the attribute, quality and category of a gem, using scientific tools is a must. There are numerous scientific tools eligible in examining gems in the area. Among them microscope, refract meter, dichromatic diagram, chemical scale and hand lens are prior in Sri Lanka. Gems graded using these scientific tools are mainly in ten categories. They are namely, Corundum , Zircon, Chrisoberil, Tourmaline, Crystal, Spinel, Beryl, Blue Sapphire, Garnet, Cat’s eye. Corundum: The category is the salience of all. This is graded into two varieties as Ruby and Sapphire. Varieties of corundum are also called commonly as sapphire. When the gem gleams in red it is classified as ruby and locally it is called “Rathu Keta”. Gem stone will be entitled as sapphire if it is blue, topaz if it is yellow, gold topaz if it is golden and ruby if it is in colour of a lotus flower. Also there are colourless varieties of corundum- white sapphire, Prussian (Kaka Nil) blue and Star sapphire are few examples for achromatic corundum. Chrisoberil: This is a special and an invaluable brand of gem. Cat’s eye, Kanaka and passingal are several varieties of chrisoberil. Passingal is the most valuable out of them but rarely found. The uniqueness of this stone is its meta spectrum. In daylight it shines green and in factitious light it shines red. That colour would come out even in daylight if a factitious light is made to penetrate the stone. Cat’s eye (Vairodi): A thin line can be seen in the interior of the stone as same as in a cat’s eye. That line is visible from every direction. Hence, this brand of gem is entitled in English as cat’s eye. Kanaka: Any kind of Meta spectrum is not visible in this variation of Chrisoberil. It has a light greenish yellow colour. Crystal: Crystal is an eminent mineral rich in Sri Lanka. Strappy cat’s eye, primrose crystal, amethyst, quartz, roseate crystal and brownish crystal are some varies of crystal plenteous in Sri Lanka. Beryl: Beryl is a very important mineral treasure. Golden beryl or Heliodorite is also a category of beryl (aquamarine; emerald). Rabaha (Almandine alias garnet): This is an abounding brand of gem in Sri Lanka. Due to the less chemical composition garnet has a less value in the field of gem. Garnet is categorized as almandine garnet, zircon, spesatyde, and pyros garnet.