Sturmanite

This thumbnail specimen features numerous sharp sturmanite crystals, exhibiting the species’ characteristic opaque beige to brown tones that give the piece a warm, earthy glow. The crystals are well-formed with distinct edges and excellent definition, making it an especially attractive thumbnail example of this rare and unusual mineral.

Sturmanite is a complex calcium–manganese–iron sulfate–borate carbonate, closely related to ettringite, and is known from only a handful of localities worldwide. Fine specimens such as this one are seldom seen on the market and are highly prized by collectors of rare species. From the international collection of Peter Tarassoff, a Canadian collector who contributed greatly to the mineralogical community.