Emerging Gem Deposits of Afghanistan was the subject of Dr. Lawrence Snee’s talk at our August meeting. Dr. Snee has been a geologist with a varied background for over 30 years and is now a member of the U.S. Geological Survey Project assisting in the reconstruction effort in Afghanistan. He has studied gem deposits all over the world, especially Asia, and has visited Afghanistan four times. Because of his familiarity with the geology and geography of Afghanistan and Pakistan he was involved in the search for Osama Bin Laden.
Blue gemstone someone brought in for show&tell
Tony Conway introducing Dr. Snee
The principal gemstones of Afghanistan are emerald, ruby, sapphire, spinel, and lapis lazuli. Spodumene, amethyst, tourmaline, morganite, aquamarine and garnet are also found as well as gold, asbestos and oil. The gem deposits occur in or near the Hindu Kush mountains (a western extension of the Himalayas) in northeast Afghanistan. Hindu Kush translates as “Slaughter of Hindus”, but that’s another story. This is an exceedingly rugged area with elevations over 25000 feet above sea level, and with steep slopes and narrow valleys typical of young mountain ranges. Mountain building is still happening here. These mountains began rising about 35 million years ago when the Indian subcontinent was transported beneath the Asian plate, and they are still rising, even as we speak. Or read. The frequent earthquakes give testimony to that. The USGS has re-interpreted much of the geology here previously done by the Russians. Under the Soviet Union, plate tectonics was not an acceptable concept.
Dr. Larry Snee speaking about Afghanistan’s gem possibilities
Geological map of northern Afganistan�
The emerald mines are located on the south side of the Panjsher Valley. This is a narrow, seventy-mile long valley coming out of the Hindu Kush and aimed at Kabul. When Snee went into this area there were 23 people in his party – three geologists and 20 armed guards. The mining is a “mom and pop” warlord operation and the mines are narrow adits hundreds of feet long with no supports. Very dangerous. The emerald is found in metamorphosed carbonate rocks. Chromium in deep-seated mafic rocks was brought into contact with beryllium bearing crustal rocks during continental collision. Hydrothermal alteration caused by beryllium bearing granitic fluids coming in contact with the chromium bearing mafic rocks formed the emeralds. Snee discussed the crystal structure and chemistry of emeralds, showed slides of inclusions including tourmaline, mica and feldspar. A trace amount of iron gives the stones a slightly bluish cast, similar to Columbian emeralds, and they are considered to be good to excellent. They are sometimes sold as Colombian.
Dr. Snee receiving our Smithsonian Gems gift book from Pres. Toby Fitzkee
And the winner of the monthly chapter raffle is………….
The unindicted raffle co-conspirators discussing the presentation
Afghan rubies and sapphires are found east of Kabul at Jegdalek and Gandamak and have been mined for more than 1000 years. On the first day Snee arrived he was prevented from entering the area, but the next day he hooked up with a warlord and got in. The rubies are found in steeply dipping marble beds, often vertical. The miners would drill down dip, parallel to the bedding, for 30 or 40 feet. The best stones are found at depth and are considered to be good to excellent. At first the miners kept the red and threw away the blue. Then they caught on. These stones are rarely identified as Afghan in the world market. These stones have mica inclusions, and mica in the host rock is an indicator of the presence of ruby.
Lapis Lazuli deposits are found in marble associated with high-grade metamorphic rocks in Badakhshan, northeast of the Panjsher Valley. Small operators have mined these deposits, located among beautiful poppy fields, for thousands of years. The Afghan lapis is famous throughout the world. Farther north on the Amu river balas ruby (spinel) has been mined in the past, but there appears to be no recent activity.
Dr. Snee plans to return to the area in the near future for continued work on the reconstruction project. This was a very enjoyable and informative talk.
Text: John Lees
Photos: Doris Voigt