Emerald mining in Afghanistan

From 1997 through 2000, a team of Polish experts headed by the author studied the prospects of mining newly discovered emerald deposits in Afghanistan. This article describes the scheme for mechanization of the mining operations, along with improvements made to the ventilation facilities and lighting. The required equipment was flown to Afghanistan and the Afghan miners were trained in machine operation and maintenance.

Afghanistan's mineral wealth

Afghanistan is rich in minerals (Abdullah and Chmyriov, 1980), which have been mined since prehistoric times using primitive techniques and tools. The oldest ornaments, found in the pyramids of Egypt, contain high-quality lapis lazuli from the region of today's Afghanistan (Badakhshan). New deposits of emeralds, rubies, and other precious and semiprecious stones were discovered recently in the wake of severe bombardments during the Soviet invasion of Afghanistan.

Access to the mountain regions of Afghanistan is difficult. Apart from larger villages, there are no infrastructure or transportation facilities. Land features make some areas inaccessible even by helicopter. Because of these logistical considerations, it is now worthwhile to exploit only those minerals that have high value in relation to their mass. Precious stones would be considered to have such value.

Emeralds are modifications of beryl. They are the product of substitutions of small amounts of chromium (Cr) for aluminum (Al) in the crystal structure.

Emeralds in Afghanistan are found mostly in the Panjsher Valley (Figs. 1 and 2) in the major fault zone at the junction of the Indo-Pakistan and Asian crustal plates. In such tectonic settings, there is contact between ultra-basic and basic rocks from the oceanic crust. These contain significant amounts of Cr. And acid intrusive rocks, such as quartz porphyry, are a good source for the beryllium-bearing hydrothermal fluids.

The emerald crystals from the Panjsher Valley differ in quality from site to site. Historically, the best stones came from the Mirkeni and Darkhenj mines in the southern part of the mining region. High-quality emeralds are also found in Khenj and Pesgur (Fig. 3).

Most emeralds occur as euhedra (in the hexagonal configuration) with the crystal form of basal pinacoids, first-order prisms and second-order prisms. Most crystals range from 4 to 5 carats, although specimens of more than 50 carats continue to be found regularly (Bowersox, 1991).

Emeralds found...