Minerals and Metals in Ancient India v1.c24.s1.t5.4

v1.c24.s1.t5.4

The last gem-mineral under the silicate family that we may discuss is tourmaline which is a complex sub-silicate of boron and aluminium, with some replacement in the structure by Mg, Fe, alkali metals and fluorine. Usually bluish black, vertically striated and of vitreous to resinous luster, tourmalines have a wide range of colour. Yellow and brown crystals are common in Sri Lanka. The name itself is derived from turamali in Ceylonese (applied to zircon by jewellers of Sri Lanka). Tourmalines of different kinds from Sri Lanka and Seringapatam used to be exported to Rome. These were mentioned as lychnis by Pliny.