Smoky quartz is a brownish grey, translucent variety of quartz that ranges in clarity from almost complete transparency to an almost-opaque brownish-gray or black crystals.[6] The color of smoky quartz is produced when natural radiation, emitted from the surrounding rock, activates color centers around aluminum impurities within the crystalline quartz. [7]
Varieties
Morion is a very dark brown to black opaque variety. Morion is the German, Danish, Spanish and Polish synonym for smoky quartz.[8] The name is from a misreading of mormorion in Pliny the Elder.[9]
Cairngorm is a variety of smoky quartz found in the Cairngorm Mountains of Scotland.[10] 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).[11] The largest known cairngorm crystal is a 23.6 kg (52 lb) specimen kept at Braemar Castle.[citation needed]
Uses
Smoky quartz is common and was not historically important, but in recent times it has become a popular gemstone, especially for jewelry.[12]
Sunglasses, in the form of flat panes of smoky quartz, were used in China in the 12th century.[13]
^ abcDeer, W. A., R. A. Howie and J. Zussman, An Introduction to the Rock Forming Minerals, Logman, 1966, pp. 340–355 ISBN0-582-44210-9
^Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (eds.). "Quartz". Handbook of Mineralogy(PDF). Vol. III (Halides, Hydroxides, Oxides). Chantilly, VA, US: Mineralogical Society of America. ISBN0962209724.
^Joseph Needham, Science & Civilisation in China (Cambridge, England: Cambridge University Press, 1962), volume IV, part 1, page 121. Needham states that dark glasses were worn by Chinese judges to hide their facial expressions during court proceedings.
