Gemstones of Pakistan: emerald, ruby and spinel.

Abstract

Three gem materials are currently mined - emerald from dolomitic talc schists in the Swat Valley, and corundum (especially ruby) and spinel from marble enclosed in gneisses and schists in the Hunza Valley. The geology, mining, recovery, and properties of each gem are given. Optical data and chemical analyses (by M. Weibel) are as follows: A) emerald (Mingora), B) ruby, and C) spinel (average of two).025TiO2 069Al2O3 115Cr2O3 165V2O3 209Fe2O3 261FeO 305MnO 360MgO 409CaO 452Na2O000A 027n.d. 074n.d. 1210.66 1680.00 2150.9 262n.d. 317n.d. 3722.6 4110.0 4642.1000B 0270.03 07499.0 1210.81 1680.02 2150.03 262n.d. 317n.d. 3720.0 4110.0 4640.0000C 0270.01 07472 1210.17 1680.33 215n.d. 2620.11 301<0.01 36427.5 411n.d. 464n.d.082epsilon 170omega 274sp. gr. 000A 0641.5905 1541.5975 2542.75-2.78 000B 0641.762 1541.770 2543.995 + or - 0.005 000C 0641.715-1.720 (range) 2543.585-3.614 441R.V.D.