Smoky quartz

Smoky quartz is a grey, translucent variety of quartz that ranges in clarity from almost complete transparency to an almost-opaque brownish-gray or black crystal. Like other quartz gems, it is a silicon dioxide crystal. The smoky colour results from free silicon formed from the silicon dioxide by natural irradiation.Morion varietyCrystals of metazeunerite perched on a complete smoky quartz crystalSmoky quartz found in a streamSmoky quartz, from Wushan Spessartine Mine, Fujian Province, ChinaA large specimen of sceptred smoky quartz from Nevada.A two-sided cluster of glassy and lustrous, doubly terminated smoky quartz crystals from recent finds in Namaqualand, South Africa. The longest crystal is 8.1 cm.This is an example of the so-called alligator quartz.A 'large' specimen from a new find in Minas Gerais. Smoky quartz is a grey, translucent variety of quartz that ranges in clarity from almost complete transparency to an almost-opaque brownish-gray or black crystal. Like other quartz gems, it is a silicon dioxide crystal. The smoky colour results from free silicon formed from the silicon dioxide by natural irradiation. Morion is a very dark brown to black opaque variety. Morion is the German, Danish, Spanish and Polish synonym for smoky quartz. The name is from a misreading of mormorion in Pliny the Elder. It has a density of 5.4. Cairngorm is a variety of smoky quartz found in the Cairngorm Mountains of Scotland. It usually has a smoky yellow-brown colour, though some specimens are greyish-brown. It is used in Scottish jewellery and as a decoration on kilt pins and the handles of sgianan-dubha (anglicised: sgian-dubhs or skean dhu). The largest known cairngorm crystal is a 23.6 kg (52 lb) specimen kept at Braemar Castle. Smoky quartz is common and was not historically important, but in recent times it has become a popular gemstone, especially for jewellery. Sunglasses, in the form of flat panes of smoky quartz, were used in China in the 12th century.