Precious and semi-precious stones have been prized for centuries for their aesthetic qualities and use in jewellery. The market for high quality stones is now quite sophisticated and they can attract higher prices than equivalent sized diamonds.
Precious Stones in Afghanistan
Afghanistan has been blessed with a great variety of precious and semi-precious stones with 73 records of mines, deposits, occurrences and showings. In fact, some of the earliest records of mining anywhere in the world are from Afghanistan, dating back over 6000 years. Most operations today are small-scale, but the potential undoubtedly exists for the development of a significant precious stone mining industry in Afghanistan. Four different stones are described below, but Afghanistan also has occurrences of other stones such as aquamarine, amethyst, and topaz.
Afghanistan is the world's leading producer of lapis-lazuli from the Sary-Sang mine in Badakhshan province. The deposit is hosted in Archean metamorphic rocks that have been intruded by alaskite granite and basic dykes. This has led to the formation of north-south skarnified zones in the calciphyre facies of the country rock. Nine zones have been identified thus far containing ten different lazurite grades, the largest being 250 m long and extending for 125 m downdip.
Emerald production from the deposits of the Panshjer valley in Kapisa province was estimated at up to $12 M in 1995. Six small mines are known within a 16 x 3 km zone consisting of Ordovician carbonates intruded by diorite-gabbro and quartz porphyry dykes. The mineralisation is confined to stockworks of quartz ankerite and dolomite within the altered units, although the best quality gems are often in veins that cross-cut gabbro and are typically up to 1.5 cm long and 3 mm thick (however larger crystals have been found). Afghan emeralds are said to be similar in quality to those of Colombia.
The Jegdalek ruby prospect in Kabul province occurs in a calcite-dolomite marble bed that has been intruded by an Oligocene granite. A ruby concentrate from the mineralised bed yielded up to 157.3 g/m3. Spinel has also been mined in Badakhshan province, close to the Tadjikistan border. Stones from here are believed to be part of the British crown jewels.
Kunzite and tourmaline crystals are found in pegmatites in the Laghman province and are associated with rare metal enrichment. The most developed deposit is that at Kolum where two irregular albitised-microcline dykes intersect a Cretaceous gabbro. The 'Main' dyke (3 km x 0.5/20 m) contains rounded cavities which contain multicoloured gem quality tourmaline. The smaller 'Kunzite' dyke (150 m x 5 m) also contains rounded cavities that can yield up to 24% gem quality kunzite stones for faceting. Quality crystals can be up to 30 x 7.5 x 1.8 cm in size.
. . . some of the earliest records of mining anywhere in the world are from Afghanistan, dating back over 6000 years . . .