Thursday, September 13, 2012

Gemstone of the Week: Sturmanite

("Sturmanite image found on wrightsrockshop.com)

Sturmanite is yet another of the under-known and under-appreciated gemstones.  It is a rare collector gem and was discovered in 1981 and is named in honour of Canadian mineralogist, Bozar Darko Sturman. Sturmanite is a Hydrated Calcium Iron Aluminum Manganese Sulfate Tetrahydroxoborate Hydroxide and related to the Ettringite group of minerals. It will generally form as dipyramidal tabular crystals or elongated hexagonal crystals and can be possibly be twinned.  It's hardness is only a 2.5, so great care needs to be taken so as not to damage it. Sturmanite may be pale or bright yellow, greenish yellow, or (if altered) brownish orange.  Sturmanite is found in South Africa.