Optimizing Face-Up Appearance in Colored Gemstone Faceting
How contrast patterns can increase perceived brightness and optimize a gemstone's appearance.
钻石的光学缺陷：快速参考表 (英语)
A simple chart on optical defects in diamond, including those that produce coloration and fluorescence colors.
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.
Fluorescence Produced by Optical Defects in Diamond
How variations in UV lamp output can affect observed fluorescence color and intensity.
Orangy Pink Coated "Soft Coral"
A coral specimen that was coated—not dyed—with a coloring agent only on the surface, an unusual method evidenced by microscopic features.
黄色“好望角”彩钻中发现鱼状内含物 (英语)
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.
Turquoise-Rock Crystal Composite
Examination of a faceted rock crystal backed by a slice of turquoise—an obvious but unusual combination of gem materials.
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