Axinite
(Ca,Fe,Mn)3Al2BO3Si4O12OH or Ca2(Fe,Mn)Al2BSi4O15(OH)IMA symbol Ax[1] Strunz classification 9.BD.20 Crystal system Triclinic Crystal class Pinacoidal (1)
(same H-M symbol) Space group P1 Identification Color Reddish brown to yellow to colorless. Blue, violet, grey. Crystal habit Tabular, wedge shaped crystals Cleavage Good on {100} Fracture Conchoidal Mohs scale hardness 6.0–7.5 Luster Vitreous Streak White Specific gravity 3.18–3.37 Optical properties Biaxial (−) Refractive index nα = 1.672–1.693
nβ = 1.677–1.701
nγ = 1.681–1.704 Birefringence δ = 0.011 Pleochroism Strong References [2][3]
(same H-M symbol)
nβ = 1.677–1.701
nγ = 1.681–1.704
Axinite is a brown to violet-brown, or reddish-brown bladed group of minerals composed of calcium aluminium boro-silicate, (Ca,Fe,Mn)3Al2BO3Si4O12OH. Axinite is pyroelectric and piezoelectric.
The axinite group includes:
- Axinite-(Fe) or ferroaxinite, Ca2Fe2+Al2BOSi4O15(OH) iron rich, clove-brown, brown, plum-blue, pearl-gray[4]
- Axinite-(Mg) or magnesioaxinite, Ca2MgAl2BOSi4O15(OH) magnesium rich, pale blue to pale violet; light brown to light pink[5]
- Axinite-(Mn) or manganaxinite, Ca2Mn2+Al2BOSi4O15(OH) manganese rich, honey-yellow, clove-brown, brown to blue[6]
- Tinzenite (CaFe2+Mn2+)3Al2BOSi4O15(OH) iron – manganese intermediate, yellow, brownish yellow-green[7]
Axinite is sometimes used as a gemstone.[8]
Gallery
- Clove-brown axinite crystals to 2.3 cm set atop matrix from the West Bor Pit at Dalnegorsk, Russia
- Chloritized bladed crystals of axinite forming on adularia from the Swiss Alps
- Tinzenite on calcite, 4.5 × 3.5 × 3 cm. Wessels Mine, Kalahari manganese fields, Northern Cape Province, South Africa
- Manganaxinite (Axinite-(Mn)), with sharp curving crystals to 4 cm. West Bor Pit at Dalnegorsk, Russia
References
Wikimedia Commons has media related to Axinite.
- ^ 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.
- ^ Axinite Archived November 19, 2008, at the Wayback Machine. Mineral Galleries
- ^ Axinite. Mindat
- ^ Handbook of Mineralogy: Ferroaxinite
- ^ Handbook of Mineralogy: Magnesioaxinite
- ^ Handbook of Mineralogy: Manganaxinite
- ^ Handbook of Mineralogy: Tinzenite
- ^ Tables of Gemstone Identification By Roger Dedeyne, Ivo Quintens p.147
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- t
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Simple | |
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Mixed |
- Axinite (borosilicate)
- Geigerite (arsenate)
- Manganese nodule (various)
- Samsonite (sulfosalt)
- Zincobotryogen (sulfate)
- Wolframite (tungstate)
- Hübnerite (tungstate)
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