Studies of pegmatitic cassiterites from the Gunung Jerai (Kedah), Bakri (Johore) and Kathu Valley (Phuket) regions

Abstract

Pegmatitic cassiterites are significantly different from cassiterite of other genetic regimes in many of their physical, geochemical and crystallographic characteristics. Such cassiterites from the 3 areas were studied and compared with one another as well as collectively compared with other types of cassiterites present in the Peninsular Malaysia and Thailand Tin Belts. Of particular significance is the discovery that biaxial positive cassiterites are abundant among the pegmatitic cassiterites studied and their distribution appears to be more widespread than previously known within the Tin Belt. Such cassiterites do not appear to be confined solely to the pegmaiitic suite though they are more likely to be so. FlaUened prismatic rhombic pegmatite cassiterites are also obtained from the lepidolite pegmatites in Phuket at the Ban Guan Tin Mine. Such cassiterites appear to have an orthohombic rather than a tetragonal symmetry.