Emerald Containing Residues of Green Polishing Compound Emeralds are commonly treated with organic fillers to reduce the visibility of fissures and thus improve their clarity (McClure et al. 1999), an...
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Natural emerald with inclusions along three directions. Recently, Guild Gem Laboratories received a 10.48 ct sugarloaf emerald (figure 1) for identification and origin determination. The refractive in...
Emeralds with highly saturated green color and pure clarity are strongly cherished and coveted by gem dealers and collectors. Those green beauties with the so called “Gota de aceite” optical phenomenon are rarer. Rarity of such samples causes the scarcity of related research on this subject. This article reports on the gemological features of one 5.1ct emerald with distinct “gota de aceite” effect. Also, the possible cause of “gota de aceite” is described and illustrated in crystalline structural perspective.
Emerald Containing Residues of Green Polishing Compound Emeralds are commonly treated with organic fillers to reduce the visibility of fissures and thus improve their clarity (McClure et al. 1999), an...
Natural emerald with inclusions along three directions. Recently, Guild Gem Laboratories received a 10.48 ct sugarloaf emerald (figure 1) for identification and origin determination. The refractive in...
Emeralds with highly saturated green color and pure clarity are strongly cherished and coveted by gem dealers and collectors. Those green beauties with the so called “Gota de aceite” optical phenomenon are rarer. Rarity of such samples causes the scarcity of related research on this subject. This article reports on the gemological features of one 5.1ct emerald with distinct “gota de aceite” effect. Also, the possible cause of “gota de aceite” is described and illustrated in crystalline structural perspective.
BANGKOK, September 7, 2026 — GUILD Gem Laboratories marked ten years of field gemology research with “A Decade in the Field,” an anniversary event held in Bangkok. Built around the theme “Mine to Mark...
‘Sugar’ Nephrite from the Altun Mountains, Xinjiang, China Nephrite has a long history and profound cultural significance in China, along with a vast consumer market. In July 2025, author YG conducted...
Grandidierite Inclusions in a Sri Lankan Sapphire Inclusions serve not only as important features for determining a gemstone's origin but also as indicators of the geological environment in which the ...