GEMSTONES

Most of the gemstone occurrences are reported from the Northern Areas of Pakistan. Although a variety of gemstone occur, but only emerald of Swat is being exploited on a substantial commercial scale at present. The Swat emerald mines are situated near the town of Mingora. The emerald bearing area is composed of low-grade metamorphic rocks of green schist facies particularly chlorite-mica schist, talc schist, graphite-quartz-mica schist and dolomite-quartz schist which are traversed by quartz veins (Ahmed, 1969). Emerald is found in the soft talc schists, which outcrop for about 1.5 km with an average thickness of 200 m. Emerald crystals occur in irregular clusters or in pockets, which do not have any orderly distribution with in the schist. Occasional emerald crystals are also found to occur in the quartz veins.

                Other places where, emerald mineralization is known include Nawe Dand in Mohmand Agency (Ahmad, 1969) and the ToraTigga(Khattakctal., 1974). At Nawe Dand the country rock is talc schist. Emerald is associated with quartz veins cutting the talc schist. The veins generally follow the foliation planes of the hostrock.At ToraTigga, the country rocks may be divided into a lower unit of grey micaceous schists inter bedded with lenses of limestone and an upper unit of green grey and black schists. A dolomite about 130 m thick occurs between these two rock units and is exposed in two outcrops, about 300 m apart. One of the dolomite outcrops has been yielding emerald from the quartz veins, which traverse the rock.The emerald bearing outcrop is1,300 m long and 600m across. Most of the veins are a few millimetres thick but some range in thickness from 10 to 30 cm. The emerald crystals occur in the veins less than 3 cm thick.

      Except for the emerald, economic potential of other known gemstones is not yet clear, however,a list

      of the report edge stone occurrences is given below:

               1. Sapphire-Illaga Khorming,iBaltistan Gilgit (Ahmad,1969)

                  Mochel, Padror,Kashmir(Ahmad,1969)

               2.Ruby-Bashe-Highar and Strakin Rondu, Baltistan, Gilgit (Ahmad, 1969). Host rock
                forruby is marble.
               3.Corundum-Timurgara,Dir(Arbabetal.,1973) Shah Dheri and Kalam,Swat(Ali,1967)
               4.Topaz-Katlang,Mardan(Arbabetal. 1972)
                  LutkhoValley,Chitral (Ahmad, 1969)
                  Haramosh Range, IskcreValley, Gilgit(Ali,1967)
               5Aquamarine-LutkhoValley,Chitral(Ali,1967)
                  Talash, Dir(Ahmad, 1969)
                  Dassu and Khaplu, Baltistan,Gilgit (Ahmad, 1969)
                  Indus Kohistan and Kaghan Valley,Hazara(Ali,1967)
                  Kel, Neelum Valley,Azad Kashmir(Ali,1967)
                6.Spinel-Baltit,HunzaValley,Gilgit (Alamand Checma,1973)
                7.Tourmaline-Khaplu,Baltistan, Gilgit(Ahmad, 1969)
                   Haramosh Range,Gilgit(Ali, 1967)
                   LutkhoValley,Chitral(Ali, 1967)
                   Swat area(Ali,(1967)
                 8.Gamet-Bash-Shigarand Khaplu, Baltistan,Gilgit (Ahmed, 1969)
                    Hazaraarea (Ali, 1967)
                    Lutkho Valley, Chitral (Ali, 1967)
                    Haramosh Range,Gilgit(Ali,1967)
                  9.Vesuvianite-Muslimbagh,Zhob(Ahmad,1969)
                    Several showings of black tourmaline, green garnet, serpentine and actinolite in
                    MalakandAgency and actinolite in lower MohmandAgency have been noticed. All
                    these mineral showings and occurrences indicate that the environment for the
                    mineralization of gemstones are favourable in the melange complex or shear zones
                    a long sutures.
                  10.Kyanite-Oghi Fort Hazara(Ali,1967)
                     Landakai,Swat (Tahirkheli, 1959).