Kaskasite
Kaskasite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula (Mo,Nb)S₂·(Mg₁₋ₓAlₓ)(OH)₂₊ₓ.
It crystallizes in the hexagonal crystal system. It is a member of the Valleriite structural group.
Key properties: Mohs hardness 1; specific gravity 3.83; Black streak; Metallic. Anisotropism: Strong luster.
IMA symbol Kks, IMA status: approved, named in 2013.
Of hydrothermal origin in fenites formed by the influence of a peralkaline fluid acting as a source of Nb on a large xenolith of alumina-rich metamorphic rocks (metapelites) located inside a huge intrusion of agpaitic nepheline syenite.
It is found associated with Orthoclase, anorthoclase, nepheline, fluorophlogopite, corundum, pyrrhotite, pyrite, rutile, monazite-(Ce), graphite, edgarite, molybdenite, tungstenite.
The name refers to Mount Kaskasnyunchorr, the locality that produced the first specimens, whose name is based on the word for “juniper” - kaskas - in the Saami language of the Kola aboriginal people.