Gem minerals include amethyst, chrysoberyl, brazilianite, topaz and quartz.
2.
Diamonds are obviously not chemically bonded carbon, extracted by smelting, but gem mineral inclusions.
3.
There are about 20 mineral species that qualify as gem minerals, which constitute about 35 of the most common gemstones.
4.
Gem minerals are often present in several varieties, and so one mineral can account for several different gemstones; for example, ruby and sapphire are both corundum, Al 2 O 3.
5.
In following years ( 1991 94 ), INSA sponsored another project on Minerals and Metals in Pre-Modern period ( 1200-1900 AD ) which led to the publication of several interesting papers in Indian J History of Science; Gem minerals in pre-Modern India, Non-Gem Minerals in Pre-modern India and Iron and Steel in Pre-modern India.
6.
In following years ( 1991 94 ), INSA sponsored another project on Minerals and Metals in Pre-Modern period ( 1200-1900 AD ) which led to the publication of several interesting papers in Indian J History of Science; Gem minerals in pre-Modern India, Non-Gem Minerals in Pre-modern India and Iron and Steel in Pre-modern India.
मोबाइल