Tangeite Explained

Tangeite
Category:Phosphate mineral
Formula:CaCu(VO4)(OH)
Imasymbol:Tg[1]
Strunz:8.BH.35
Dana:41.05.01.06
System:Orthorhombic
Class:Disphenoidal (222)
H-M symbol: (2 2 2)
Symmetry:P212121
Unit Cell:a = 7.45 Å, b = 9.26 Å
c = 5.91 Å; Z = 4
Color:Yellow, yellow-green, olive green, green to dark green
Habit:Rarely as short prismatic crystals, commonly as fibrous to botryoidal encrustations
Cleavage:Perfect on, good on
Tenacity:Brittle
Mohs:3.5
Luster:Vitreous, pearly on cleavage faces
Streak:Light yellow green
Diaphaneity:Transparent, Translucent
Gravity:3.75 - 3.84
Opticalprop:Biaxial (-)
Refractive:nα = 2.010 nβ = 2.050 nγ = 2.090
Birefringence:0.08
2V:83° (measured)
References:[2] [3] [4]

Tangeite, also known as calciovolborthite, is a calcium, copper vanadate mineral with formula: CaCu(VO4)(OH). It occurs as a secondary mineral that can be found in sandstone and also in the oxidized zones of vanadium bearing deposits.

It was named in 1925 by Aleksandr Evgenievich Fersman for its discovery locality in the Tange Gorge, Ferghana Valley, Alai Mountains, Kyrgyzstan.[2]

Notes and References

  1. Warr. L.N.. 2021. IMA–CNMNC approved mineral symbols. Mineralogical Magazine. 85. 3. 291–320. 10.1180/mgm.2021.43. 2021MinM...85..291W. 235729616. free.
  2. http://www.mindat.org/min-4073.html Tangeite
  3. http://webmineral.com/data/Tangeite.shtml Tangeite data
  4. http://rruff.info/doclib/hom/tangeite.pdf Handbook of Mineralogy