Cubanite

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Cubanite
Cubanite-47299.jpg
Striated, cyclically-twinned cubanite crystals from the Chibougamau mines of Quebec. (size: 1.5 x 1.3 x 1.0 cm)
General
Category Sulfide mineral
Formula
(repeating unit)
CuFe2S3
Strunz classification 02.CB.55a
Crystal symmetry Orthorhombic (2/m 2/m 2/m) - dipyramidal
Unit cell a = 6.467(1) Å, b = 11.117(1) Å, c = 6.231(2) Å; Z = 4
Identification
Color Bronze to brass-yellow
Crystal habit Crystals elongated to thick tabular, striated also massive
Crystal system Orthorhombic
Twinning Common with twin plane {110} in pairs, also as fourlings and pseudohexagonal sixlings
Cleavage Parting on {110} and {130}
Fracture Conchoidal
Mohs scale hardness 3.5-4
Luster Metallic
Streak Black
Diaphaneity Opaque
Specific gravity 4.0-4.2
Optical properties Distinctly anisotropic on polished surface
Other characteristics Strongly magnetic
References [1][2][3]
Iridescent and highly lustrous brass-yellow cubanite crystal from Chibougamau, Quebec (size: 1.7 x 1.0 x 0.7 cm)

Cubanite is a yellow mineral of copper, iron, and sulfur, CuFe2S3.[3]

Cubanite was first described in 1843 for an occurrence in the Mayarí-Baracoa Belt, Oriente Province, Cuba.[1]

Cubanite occurs in high temperature hydrothermal deposits with pyrrhotite and pentlandite as intergrowths with chalcopyrite. It results from exsolution from chalcopyrite at temperatures below 200 to 210 °C.[2] It has also been reported from carbonaceous chondrite meteorites.[2]

References[edit]

  • Schumann, Walter (1991). Mineralien aus aller Welt. BLV Bestimmungsbuch (2 ed.). p. 223. ISBN 3-405-14003-X.