Valentinite

Valentinite
A sample of valentinite from Algeria (size: 6.9 x 4.4 x 3.3 cm)
General
CategoryOxide minerals
Formula
(repeating unit)
Sb2O3
IMA symbolVln[1]
Strunz classification4.CB.55
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPccn
Unit cella = 4.91 Å, b = 12.46 Å
c = 5.42 Å; Z = 4
Identification
ColorColorless, snow-white, pale yellow, pink, gray to brownish
Crystal habitPrismatic crystals, sometimes flattened, fan-shaped or stellate aggregates of crystals; lamellar, columnar, granular, massive.
Cleavage{110}, perfect; {010}, imperfect
TenacityBrittle
Mohs scale hardness2.5–3
LusterAdamantine, pearly on cleavages
StreakWhite
DiaphaneityTransparent to translucent
Specific gravity5.76
Optical propertiesBiaxial (−)
Refractive indexnα = 2.180 nβ = 2.350 nγ = 2.350
Birefringenceδ = 0.170
2V angleVery small
References[2][3][4]

Valentinite is an antimony oxide mineral with formula Sb2O3. Valentinite crystallizes in the orthorhombic system and typically forms as radiating clusters of euhedral crystals or as fibrous masses. It is colorless to white with occasional shades or tints of yellow and red. It has a Mohs hardness of 2.5 to 3 and a specific gravity of 5.76.[5] Valentinite occurs as a weathering product of stibnite and other antimony minerals. It is dimorphous with the isometric antimony oxide senarmontite.[2]

  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. ^ a b Handbook of Mineralogy
  3. ^ Mindat with location data
  4. ^ Webmineral data
  5. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8