Minerals and Metals in Ancient India v2.c43.s3.t10.10

v2.c43.s3.t10.10

We may briefly comment on fine yellowish-green or golden yellow chrysolite (French jewellers call it peridot), which is precious olivine or a gem variety of the group of mineral called olivine R₁²⁺ R₂²⁺ (SiO₄) wherein R₁ and R₂ could be various combinations of Mg, Fe, Ca and Mn. Chrysolite contains more of Mg and Fe²⁺ accounting for the typical colour. Its hardness is 6-3/4; it is slightly softer than quartz and its specific gravity is 3.33-3.37, more than that of emerald. At present, the reserves of the gem probably stand exhausted, but in the ancient world, it was well-known and created some confusion with emerald (green) and topaz (yellow), all the three gem minerals occurring together between the Nile and the Red Sea. E.S. Dana has commented that ‘the chrysolithus of Pliny was probably our topaz and his topaz our chrysolite’. The two different materials could be easily distinguished in terms of their hardness, topaz being much harder.