Purplish Pink Spinel from Tajikistan: Before and After Cutting
Read MoreThe heat treatment of corundum involving lattice diffusion of beryllium (Be) at temperatures over 1800°C has become a major issue in the gem trade.
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This study provides detailed mining and gemmological information on the Jegdalek deposit, in east-central Afghanistan, which is hosted by elongate beds of corundum-bearing marble.
Read MoreLocated just 3 km south of the famous Umba locality, the geologically similar Kalalani area hosts deposits of gem-quality sapphire.
Read MoreResearchers from the Tairus joint venture have developed the technology for the hydrothermal growth of gem-quality crystals of synthetic sapphire.
Read MoreGem-quality rubies and fancy-colour sapphires have been recovered from dolomite marble lenses located high in the Himalayan mountains of east-central Nepal (Ganesh Himal).
Read MoreSince 1993, large amounts of gem-quality sapphires from the Andranondambo region of southern Madagascar have entered the international gem market.
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Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States.
Read MoreRenewed interest in large-scale commercial mining of Montana sapphires motivated a detailed study of the heat treatment of sapphire from the Rock Creek deposit.
Read MoreBlue diffusion-treated sapphires have become a subject of considerable controversy since their introduction in significant quantities a few years ago.
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