Optimizing Face-Up Appearance in Colored Gemstone Faceting
How contrast patterns can increase perceived brightness and optimize a gemstone's appearance.
ダイヤモンド中の光学的欠陥:早見表 (英語)
A simple chart on optical defects in diamond, including those that produce coloration and fluorescence colors.
Fluorescence Produced by Optical Defects in Diamond
How variations in UV lamp output can affect observed fluorescence color and intensity.
Nephrite Jade from Val Malenco, Italy: Review and Update
Analysis of 21 rough and gem-quality samples offers an update on the composition and properties of this pale green gem from the Italian Alps.
Orangy Pink Coated "Soft Coral"
ファンシーイエロー・ケープダイヤモンドの中に魚のような内包物を発見 (英語)
A recent lab examination at GIA New York revealed an inclusion in a rectangular Fancy Yellow called "pareidolia," which means it was a resemblance of the scales and form of a fish.
Rare Faceted Neptunite
Raman spectroscopy reveals orangy red neptunite in identification of a 11.78 ct faceted “black” octagonal modified step-cut stone.

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