Smoky Quartz
Light brown to almost black variety of quartz.
Very dark to almost black smoky quartzes are also known as morion.
Origin of name: after its colour.
The name morion is a corruption of the word mormorion, a name used by Pliny the elder in his monumental work Naturalis Historia. In volume 6, book 37, chapter 63 he describes mormorion as a transparent stone from India, of a deep black colour, and known also as “promnion.”
Synonyms and trade names: besides morion one occasionally encounters the name Cairngorm for smoky quartz from the Scottish Cairngorm Mountains. Cairngorm is quite popular in Scotland and is used in jewellery, for kiln pins and the handles of the so-called sgian-dubh (gaelic for black knife, where black has the secondary meaning of "hidden").
Thank goodness these misleading term smoky topaz, which was an accepted trade name, is hardly encountered any moe (and should be abandoned altogether).
Can be confused with: other minerals of similar colour like topaz, brown tourmaline (dravite, brown zircon e.a.
Localities: very common. Far more than 2000 localities on all continents except Antarctica are known
Handling: smoky quartz is sensitive to high temperatures and to UV light. Keep away from heat and from elongated exposure tu UV light. Solder with care! Colour change may appear at temperatures as low as 200°C.
Sensitive to hydrofluoric acid only.
Smoky quartz has no or only very weak cleavage and thus is unproblematic during setting
Two smoky quartzes of unusual colour (left) and unusual cut (right)
Worth knowing: smoky quartz gets its colour from natural or man made irradiation. Natural irradiation is caused by the decay of radioactive substances in its vicinity. The irradiation produces defects in the crystal lattice which act as colour centers.
Irradiation, when properly done, does not produce radioactive isotopes in the stone so it does not become radioactive itself and emits radiation way below any critical limit
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