Bronze yellowish brown crystal aggregates of the very rare sulphide mineral isocubanite from a big depth in the Pacific Ocean (Guaymas Basin, Pacific Ocean, United States of America) in a completely analyzed specimen by SEM/EDS, associated to golden chalcopyrite and pyrrothite. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Isocubanite
Isocubanite is an IMA-recognized mineral species in the sulfide class, with the chemical formula CuFe₂S₃.
It crystallizes in the cubic crystal system (space group F-43m). It is a member of the Cubanite, Sphalerite structural group.
Key properties: specific gravity 3.93; Metallic. R: (400) 20.9, (420) 22.7, (440) 24.6, (460) 26.9, (480) 29.2, (500) 31.4, (520) 33.2, (540) 34.8 luster.
IMA symbol Icb, IMA status: approved, named in 1983.
Found in mixtures of sulfides formed around modern undersea “black smoker” chimneys; in hydrothermal copper sulfide deposits; in pumice from volcanic eruptions.
It is found associated with Chalcopyrite, pyrrhotite, pyrite, sphalerite, wurtzite, anhydrite.
The name refers to the cubic structure and relation to cubanite.