Kochite
A rare zirconium-titanium sorosilicate of the rosenbuschite group, found in alkaline intrusions.
Intro adapted from Wikipedia (CC BY-SA).
Kochite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₂MnZrNa₃Ti(Si₂O₇)₂(OF)F₂.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Seidozerite-Rinkite structural group.
Key properties: Mohs hardness 5; specific gravity 3.32; Vitreous luster; refractive index 1.699; optically biaxial.
IMA symbol Koh, IMA status: approved, named in 2002.
An accessory phase in nephline syenite in an alkaline complex.
It is found associated with Nepheline, alkali feldspar, låvenite.
The mineral was named to honor Danish geologist Lauge Koch (1892-1964), who mapped Werner Bjerge.