Freboldite
Freboldite is an IMA-recognized mineral species in the sulfide class, with the chemical formula CoSe.
It crystallizes in the hexagonal crystal system (space group P6_3mc). It is a member of the Nickeline structural group.
Key properties: Mohs hardness 6; specific gravity 7.7.
IMA symbol Fbd, grandfathered status — known before the IMA’s founding, named in 1957.
Found in dolostone veinlets (Steinbruch, Germany).
It is found associated with Clausthalite, nickeline, guanajuatite, hastite, trogtalite, bornhardtite, chalcopyrite, millerite, sphalerite, hematite.
In honor of Professor Georg Frebold (1891–?) of Hannover, Germany.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
Browse more F minerals or help write this entry.