Ferrobustamite Field of view: 0.5 mm high Locality: Lichtloch 25, Hettstedt, Mansfeld-Südharz, Saxony-Anhalt, Germany — Photo: Henk Smeets – tomeikminerals.com · CC BY 4.0
Ferrobustamite
Ferrobustamite is an IMA-recognized mineral species in the silicate class, with the chemical formula CaFe²⁺Si₂O₆.
It crystallizes in the triclinic crystal system (space group A-1). It is a member of the Wollastonite structural group.
Key properties: Mohs hardness 6; specific gravity 3.09; optically biaxial.
IMA symbol Fbst, grandfathered status — known before the IMA’s founding, named in 1937.
Surrounding chert nodules in a skarn in dolostone (Isle of Skye, Scotland).
It is found associated with Hedenbergite, grossular-andradite (Isle of Skye, Scotland).
The name refers to FERROan iron in its composition and its relation to bustamite.