Alabandite
Group of octahedral alabandite crystals partially coated with pink rhodochrosite, from Uchucchacua Mine, Oyon, Lima, Peru (size: 60 mm × 59 mm × 46 mm, 204 g)
General
CategorySulfide mineral
Formula
(repeating unit)		MnS
IMA symbolAbd[1]
Strunz classification2.CD.10 (10 ed)
II/C.15-30 (8 ed)
Dana classification2.8.1.4
Crystal systemCubic
Crystal classHexoctahedral (m3m)
H-M symbol: (4/m 3 2/m)
Space groupFm3m
Unit cella = 5.2236 Å; Z = 4
Identification
Colorblack, steelgray, brownish-black
Crystal habitmostly massive or granular; cubic or octahedral crystals to 1 cm
TwinningLamellar || {111}
CleavagePerfect on {100}
FractureIrregular, uneven
TenacityBrittle
Mohs scale hardness3.5 to 4
LusterSub-metallic
StreakGreen
DiaphaneityOpaque, translucent in thin fragments
Specific gravity4.053
Optical propertiesIsotropic
Refractive indexn = 2.70
References[2][3]

Alabandite or alabandine is a rarely occurring manganese sulfide mineral. It crystallizes in the cubic crystal system with the chemical composition Mn2+S and develops commonly massive to granular aggregates, but rarely also cubic or octahedral crystals to 1 cm.

Etymology and history

Alabandite was first described in 1784 by Franz-Joseph Müller von Reichenstein.[4] The mineral name is derived from its supposed discovery locality at Alabanda (Aïdin) in Turkey.[3]

Occurrence

Alabandite forms in epithermal polymetallic sulfide veins and low-temperature manganese deposits. It occurs with acanthite, calcite, chalcopyrite, galena, pyrite, quartz, rhodochrosite, rhodonite, sphalerite and native tellurium. Sometimes it was found in meteorites.[2]

Localities are several areas in Antarctica, Argentina, Armenia, Australia, Bolivia, Brazil, Bulgaria, Canada, China, Czech Republic, Finland, France, Germany, Ghana, Greece, Greenland, India, Italy, Japan, Kyrgyzstan, Mexico, New Zealand, Norway, Peru, Poland, Romania, Russia, Slovakia, South Africa, South Korea, Sweden, Switzerland, Taiwan, Tanzania, the United Kingdom, the US, Uzbekistan and Yemen. All together at present time approximately 220 discovery sites are registered.

Crystal structure

Alabandite crystallizes in the cubic crystal system in the space group Fm3m with the lattice parameter a = 5.22 Å[5] and four formula units per unit cell.[2]

See also

References

  1. ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. 1 2 3 Handbook of Mineralogy
  3. 1 2 Mindat.org
  4. ↑ "www.mineral.hermuz.hu - A Kárpát-övezetben felfedezett ásványok". Archived from the original on 2016-03-03. Retrieved 2010-01-15.
  5. ↑ American Mineralogist Crystal Structure Database - Alabandite (1991)
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