Spectral and Chemical Analysis of Pink-Green Bicolor Tourmaline HUANG Tiantian, GAO Yujie Abstract: Seventeen pink-green bicolored tourmaline samples were studied by standard gemological testing, Four...
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A Pink Sapphire with Questionable Heat Treatment A pink sapphire weighing over 20 ct was recently submitted to Guild Gem Laboratories, and it presented a particularly challenging case for the determin...
Bicoloured Jadeite-Omphacite Jade from Guatemala Traditionally, jadeite-omphacite jade (fei cui) from Myanmar prevails in the Chinese market, although in recent years material from Guatemala has drawn...
Spectral and Chemical Analysis of Pink-Green Bicolor Tourmaline HUANG Tiantian, GAO Yujie Abstract: Seventeen pink-green bicolored tourmaline samples were studied by standard gemological testing, Four...
A Pink Sapphire with Questionable Heat Treatment A pink sapphire weighing over 20 ct was recently submitted to Guild Gem Laboratories, and it presented a particularly challenging case for the determin...
Bicoloured Jadeite-Omphacite Jade from Guatemala Traditionally, jadeite-omphacite jade (fei cui) from Myanmar prevails in the Chinese market, although in recent years material from Guatemala has drawn...
Fayalite Inclusion in Guatemalan Jadeite-Omphacite Jade Figure 1: The jadeite-omphacite cabochon in this pendant (29.40 x 20.87 mm) was found to contain some interesting inclusions. Photo by Siqi Luo...
An Assembled ‘Emerald’ Rough New gem discoveries invariably generate considerable interest within the industry. Recently, a specimen was submitted to Guild Gem Laboratories in Shenzhen as a purported ...
Advanced Instrumentation for Identifying Sugar-Acid-Treated Opal Black opal is commonly more highly valued than white opal because the dark background makes the play-of-colour appear more prominent. T...