Traskite (brown) and Kampfite (bluish), from Big Creek, Fresno County, California, United States of America — Photo: David Hospital - www.purple-sky-minerals.com · CC BY-SA 3.0
Traskite
Traskite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ba₂₁Ca(Fe²⁺,Mn,Ti)₄(Ti,Fe,Mg)₁₂(Si₁₂O₃₆)(Si₂O₇)₆(O,OH)₃₀Cl₆·14H₂O.
It crystallizes in the hexagonal crystal system (space group P-6m2).
Key properties: Mohs hardness 5; specific gravity 3.71; Pale reddish brown streak; Vitreous luster; optically uniaxial.
IMA symbol Tsk, IMA status: approved, named in 1964.
Occurs as local concentrations in thin layers in metamorphic sanbornite-quartz rock.
It is found associated with Sanbornite, quartz, celsian, diopside, taramellite, fresnoite, muirite, verplanckite, pyrrhotite, pyrite.
The name refers to Dr. John Boardman Trask (1824–1879), first California State Geologist (1850–1857).