April Birth Stone: Diamond

The birthstone for April is Diamond. Its name refers to its hardness (Greek-Adamas, unconquerable). Diamond is generally acknowledged as the most precious of gems. One reason for this is that it is the hardest known natural material. This extreme hardness along with high luster and single refractive quality gives the diamond its beauty.

Diamond has a high refractive index and dispersion, optical properties that account for the extraordinary brilliance and fire of a well cut diamond. Because of its unsurpassed hardness diamond is not only valued as a Gem but has many important industrial uses. Of the four varieties of diamond three are industrial types.

Diamonds are the only gem material that is mined by highly mechanized, large scale methods. With annual production of over 60 million carats, 80% is industrial diamond. DeBeers Consolidated Mines Limited, through its Central Selling Organization, markets 80% of the worlds diamond production. DeBeers operates mines in southern Africa, and through the Diamond Corporation, contracts with other producers for the purchase of their production.

These, and other diamonds purchased on the open market in Africa and elsewhere (U.S.S.R, Australia, ect.) are sold through the Central Selling Organization in London. These diamonds are sold at annual meetings of "sight Holders" in London several times a year. Only 250 to 300 diamond manufactures are invited to these meeting through brokers to buy lots of pre sorted unseen parcels of diamonds, called sights, at fixed prices against cash.

Each buyer must purchase all or most of the parcels, they can not be refused, or risked not being invited back for the next sight! Each parcel is worth about $42,500, and there are many many parcels.

Further sales and sorting of the parcels are handled by members of diamond bourses and diamond clubs or by wholesalers. Bourses can be found in Antwerp, Amsterdam, New York, Ramat Gan (Israel), as well in Los Angeles, New York, ect. Diamond bourses are not exchanges in their usual sense, but are more like diamond wholesale markets. They are internationally federated and submit to strict rules. Through the Central Selling Organization, producers control prices of rough diamonds to maintain the value of diamonds.

Diamond are sold based on the four C's; Cut, Color, Clarity, Carat Weight. Please see the 4'cs section of the web page for detail explanation.

Diamonds are mined in primary deposits, called Kimberlite pipes, and in washed out diamondiferous placers-called alluvial deposits. Historically most diamonds came from India & Borneo. Modern production comes for South Africa, the Atlantic cost of Africa, Nabia, Brazil, Russia (Siberia), and Australia.

Diamonds occur in a variety of natural colors beside the normal colorless to off yellow gem variety. These type of diamonds are called Fancy Color or fancies. The fancy color diamonds are quite rare and extremely expensive. Diamond are found in shades of red, pink, orange, green, yellow, blue and brown. When the color is deep and intense they are called Fancy Vivid.

Example of vivid famous diamonds are the 44.5 carat Fancy Vivid Blue Hope Diamond, the 41 carat Vivid Fancy green Dresden diamond, and the 128.51 carat vivid orange yellow Tiffany diamond. The greatest rough diamonds suitable for gem stones were the Cullinan, 3106 carats, The Excelsior, 995.2 carats, Star of Sierra Leone, 968.9 carats, Great Mogul, about 800 carats, Woyie River, 770 carats, President Vargas, 26.6 carats, Jonker, 726 carats, Jubilee, 650.8 carats, Dutoitspan, 616 carats, and the Baumgold, 609 carats.

The worlds largest faceted diamond is the Cullian 1 and is 530.20 carats and is one of the 104 diamonds fashioned from the 3,106 carat rough Cullinan. It is mounted on the scepter of King Edward VII in the tower of London; it is also called the Star of Africa.

Gem Auctions At ThaiGemStore