Sakuraiite ore exhibited at the Mining Museum of Akita University — Photo: 掬茶 · CC BY-SA 4.0
Sakuraiite
Sakuraiite is an IMA-recognized mineral species in the sulfide class, with the chemical formula (Cu,Zn,Fe)₃(In,Sn)S₄.
It crystallizes in the cubic crystal system. It is a member of the Sphalerite, Stannite structural group.
Key properties: Mohs hardness 4; specific gravity 4.45; Lead-gray with olive tint streak; Metallic. Anisotropism: Nearly isotropic. R1 –R2: (400) 22.5, (420) 22.5, (440) 22.5, (460) 22.6, (480) 22.6 luster.
IMA symbol Sak, IMA status: approved, named in 1965.
Found in a banded hydrothermal vein.
It is found associated with Stannite, sphalerite, chalcopyrite, cassiterite, matildite, cobaltian arsenopyrite, quartz, calcite.
The mineral was named to honor Dr. Kin-ichi Sakurai (1912–1993), Japanese mineral collector.