Borate minerals

Large (up to 1.8 cm) yellow londonite crystals associated with rubellite tourmaline. Londonite is an unusual caesium-rich heptaborate.[1]

The borate minerals are minerals which contain a borate anion group. The borate (BO3) units may be polymerised similar to the SiO4 unit of the silicate mineral class. This results in B2O5, B3O6, B2O4 anions as well as more complex structures which include hydroxide or halogen anions.[2] The [B(O,OH)4] anion exists too.


Many borate minerals, such as borax, colemanite, and ulexite, are salts: soft, readily soluble, and found in evaporite contexts. However, some, such as boracite, are hard and resistant to weathering, more similar to the silicates.

There are over 100 different borate minerals.[2][3] Borate minerals include:

Nickel–Strunz Classification -06- Borates

IMA-CNMNC proposes a new hierarchical scheme (Mills et al., 2009). This list uses it to modify the Classification of Nickel–Strunz (mindat.org, 10 ed, pending publication).

Class: borates

Subclass: nesoborates

Subclass: inoborates

Subclass: phylloborates

Subclass: tektoborates

See also

References

  1. Londonite at Mindat.org
  2. 1 2 Klein, Cornelis and Cornelius Hurlbut, Jr., Manual of Mineralogy, Wiley, 20th ed., 1985 pp. 343 - 347 ISBN 0-471-80580-7
  3. Webmineral.Com, Strunz group V/G - V/L

External links

Media related to Londonite at Wikimedia Commons

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