28 May The Internal World of Afghan Emeralds
#repost from GIA Gems and Gemology, winter 2019 magazine:
The Internal World of Afghan Emeralds. While Afghan emeralds have never held the market share of their Colombian brethren, many fine stones have been produced from the mines in the Panjshir Valley (figure 9). As for their internal characteristics, multiphase fluid inclusions are the most common inclusion in Afghan emeralds. They often have an elongate, needle-like shape and host several daughter minerals (figures 10 and 11), which can distinguish them from Colombian and Chinese emeralds. Daughter minerals in fluid inclusions in emeralds are often assumed to be halite when they have a cubic habit; however, when there are several daughter minerals, as in the inclusions in Afghan emeralds, their exact identity is often hard to determine, even with the use of confocal Raman spectroscopy. The typical inclusion scene in these emeralds from the Panjshir Valley consists of small jagged fluid inclusions (figures 12 and 13), similar to those seen in Colombian emeralds, and scarce crystalline inclusions. Solid inclusions, when present, include pyrite, limonite, beryl, carbonate minerals, and feldspar.