The process begins with the rough crystal. Crystals come in many different shapes and forms. Some are still in their “crystal habit” (the natural form in which a particular gem mineral develops) others have been broken by the mining process or by nature itself with the twisting of the rock in which it formed. Others still, are alluvial and carry the appearance of water worn pebbles.
Less rare gems, produced in quantity and smaller sizes are often cut as calibrations – standard sizes. In the case of these cuts, the principal consideration is a uniform size – an 8 x 6 oval for example. However, with fine, rare gemstones, the shape of the rough generally dictates the eventual shape of the finished piece, rather than any allusion to a standard size. This is because fine gemstones are very rare and expensive and a cutter will try to maximize the yield he gains from a piece of rough in order to minimize loss of weight – weight is money. Balancing the need to maintain weight and the importance of good proportions to create good light return is the cutter’s eternal challenge. Stones which are cut purely to maintain weight and do not take into consideration symmetry, beauty and brilliance are not considered to be top grade – and a bad cut can ruin a very good piece of rough.
Rare Gems from Burma 