Small but outstanding crystal group of the very rare sulphosalt mineral launayite in an analyzed specimen by SEM/EDS from the type locality in Canada (Taylor Pit, Huntingdon Township, Madoc, Hastings County, Ontario, Canada). Madoc is known for being the Sb-equivalent of the Lengenbach deposit (where sulphosalts there, are always the As equivalents). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Launayite
Launayite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula CuPb₁₀(Sb,As)₁₃S₂₀.
It crystallizes in the monoclinic crystal system. It is a member of the Madocite structural group.
Key properties: specific gravity 5.83; Black streak; Metallic luster.
IMA symbol Lau, IMA status: approved, named in 1966.
Of hydrothermal origin, in marbles.
It is found associated with Veenite, boulangerite.
The name refers to Professor Louis Alphonse Auguste de Launay (1860–1938), French student of mineral deposits, National School of Mines, Paris, France.