Minerals and Metals in Ancient India v1.c24.s1.t5.3

v1.c24.s1.t5.3

Another orthosilicate (of zirconium), Zircon, ZrSiO₄ is often brownish due to the trace impurity of iron oxide. Hyacinth or jacinth is the orange, or red variety of zircon (a variety of garnet also is known as hyacinth). Colourless or smoky variety of zircon is called jargon. Gemstones made out of the above materials from the gem-gravels of Sri Lanka were widely used in the Roman empire. There is a fine model of a bull and other fine jacinths, and cameos which indicate Roman trade with Sri Lanka.