Outstanding sharp bronze crystals of the rare sulphide mineral matildite from the famous Clara mine (Wolfach, Black Forest, Baden-Württemberg, Germany). — Photo: David Hospital · CC BY-SA 4.0
Matildite
Matildite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula AgBiS₂.
It crystallizes in the hexagonal crystal system.
Key properties: Mohs hardness 2.5; specific gravity 6.9; Pale gray streak; Metallic luster.
IMA symbol Mtd, IMA status: approved, named in 1883.
Formed in hydrothermal deposits at medium to high temperatures and in pegmatites.
It is found associated with Galena, pavonite, aikinite, bismuthinite, hessite, tetradymite, pyrite, chalcopyrite, sphalerite, arsenopyrite, tetrahedrite.
The name refers to its occurrence in the Matilda mine, Peru.