EOSC 118 Lecture Notes - Lecture 11: Gemology, Blood Diamond, Gemstone
4 Aug 2015
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Document Summary
Cut and polished diamonds evaluated by 4 primary variables: cut, clarity, colour, carat. The 4c system introduced by de beers in late 1930"s. Variations on the 4cs also used for other gemstones, but not to the same extent as diamonds. There is heat generated through the polishing and it shatters when you try and cut it. Natural optics and the way the facets are cut. The pavilion is the bottom half of the gem, and it takes the light and reflects it back onto your face, which gives it its sparkle. Flawless (fl): no blemishes or inclusions when examined by a skilled grader under 10x magnification. Internally flawless (if): no inclusions when examined by a skilled grader, and only insignificant blemishes under 10x. Very very slightly included (vvs1 > vvs2): contains minute inclusions that are difficult for even a skilled grader to locate under 10x.
