Kassite

Kassite
General
Category Hydroxide mineral
Chemical formula CaTi2O4(OH)2
Strunz classification 04.DH.10
Identification
Molar mass 235.09
Color Brown red, colorless, light yellow
Crystal habit Pseudo hexagonal
Crystal system Monoclinic - Prismatic (2/m), space group: P21/a
Cleavage {010} Perfect
Fracture Brittle
Mohs scale hardness 5
Luster Adamantine
Streak White
Specific gravity 3.42
Optical properties Biaxial (–), 2V=58°, Dispersion very strong, r > v
Refractive index nα = 1.95, nβ = 2.13, nγ = 2.21
Birefringence δ = 0.26
Pleochroism none
Other characteristics Not radioactive
References [1][2]

Kassite is a rare mineral with formula CaTi2O4(OH)2. It crystallizes in the orthorhombic crystal system and forms radiating rosettes and pseudo-hexagonal tabular crystals which are commonly twinned. Crystals are brownish pink to pale yellow and are translucent with an adamantine luster. Cleavage is distinct and the crystals are very brittle.

It was first described in 1965 from the Afrikanda pyroxenite massif, Kola Peninsula, Russia and was named for Nikolai Grigorievich Kassin (1885–1949), Russian geologist. It occurs as miarolytic cavity fillings of alkalic pegmatites in the Kola occurrence and in nepheline syenite in the Magnet Cove igneous complex of Arkansas, USA. Its mineral association includes cafetite, perovskite, titanite, rutile and ilmenite. It is polymorphous with cafetite.

References