How do I identify Sturmanite?

Sturmanite can be identified by its hardness of 2.5 on the Mohs scale, Bright Yellow to amber color. Look for these key characteristics when examining specimens.

What color is Sturmanite?

Sturmanite typically appears in Bright Yellow to amber. Color can vary depending on impurities and formation conditions.

How hard is Sturmanite?

Sturmanite has a hardness of 2.5 on the Mohs scale. This makes it a soft mineral that can be scratched easily.

Sturmanite

A variety of Minerals

What is Sturmanite?

Sturmanite is a rare sulfate mineral with the chemical formula Ca6Fe2(SO4)2.5(B(OH)4)(OH)12 · 25 H2O. It crystallises in the tetragonal system and it has a Moh's hardness of 2.5. Sturmanite has a bright yellow to amber colour and falls in the ettringite group. It was named after Bozidar Darko Sturman (born 1937), Croatian-Canadian mineralogist and Curator Emeritus of Mineralogy, Royal Ontario Museum.

Sturmanite Market Value Calculator

Estimate the market value of Sturmanite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.

Sturmanite Localities Map

See where Sturmanite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

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North ZoneCentral RidgeSouth Basin

Key Characteristics

Formation of Sturmanite

Sturmanite was first identified in 1983 and approved by the IMA in the same year. It was first found in the Black Rock Mine, Black Rock, Kalahari manganese field, Northern Cape Province, South Africa. It is found as flattened dipyramidal crystals on hematite and baryte. Sturmanite has also been identified in mines near the Black Rock Mine, such as the Wessel's and Perth mines, in the N'Chwaning mines, and near Lakargi Mountain in Russia. It is found as a rare secondary mineral embedded in manganese deposits and is associated with baryte, manganite, hausmannite, and hematite.

Composition of Sturmanite

The crystal structure of sturmanite shows two distinct features: one being columns of iron-octahedra and calcium polyhedra, the other being the SO4 and B(OH)4 tetrahedra surrounding these columns. These two structures are linked together through a dense and complex network of hydrogen bonds.