Borate minerals

File:Londonite-Tourmaline-120977.jpg

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

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. 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. Borate minerals include:

• Kernite Na₂B₄O₆(OH)₃·3H₂O
• Borax Na₂B₄O₅(OH)₄·8H₂O
• Ulexite NaCaB₅O₆(OH)₆·5H₂O
• Colemanite CaB₃O₄(OH)₃·H₂O
• Boracite Mg₃B₇O₁₃Cl

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).

• Abbreviations:
  • "*" - discredited (IMA/CNMNC status).
  • "?" - questionable/doubtful (IMA/CNMNC status).
  • "REE" - Rare-earth element (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu)
  • "PGE" - Platinum-group element (Ru, Rh, Pd, Os, Ir, Pt)
  • 03.C Aluminofluorides, 06 Borates, 08 Vanadates (04.H V^[5,6] Vanadates), 09 Silicates:
    • Neso: insular (from Greek νησος nēsos, island)
    • Soro: grouping (from Greek σωροῦ sōros, heap, mound (especially of corn))
    • Cyclo: ring
    • Ino: chain (from Greek ις [genitive: ινος inos], fibre)
    • Phyllo: sheet (from Greek φύλλον phyllon, leaf)
    • Tekto: three-dimensional framework
• Nickel–Strunz code scheme: NN.XY.##x
  • NN: Nickel–Strunz mineral class number
  • X: Nickel–Strunz mineral division letter
  • Y: Nickel–Strunz mineral family letter
  • ##x: Nickel–Strunz mineral/group number, x add-on letter

Class: borates

• 06. Alfredstelznerite
• 06.A Monoborates
  • 06.AA BO₃, without additional anions; 1(D): 05 Sassolite; 15 Nordenskioldine, 15 Tusionite; 35 Jimboite, 35 Kotoite; 40 Takedaite
  • 06.AB BO₃, with additional anions; 1(D) + OH, etc.: 05 Hambergite, 10 Berborite, 15 Jeremejevite; 20 Warwickite, 20 Yuanfuliite; 25 Karlite; 30 Azoproite, 30 Bonaccordite, 30 Fredrikssonite, 30 Ludwigite, 30 Vonsenite; 35 Pinakiolite; 40 Blatterite, 40 Orthopinakiolite, 40 Takeuchiite, 40 Chestermanite; 45 Hulsite, 45 Magnesiohulsite, 45 Aluminomagnesiohulsite; 50 Hydroxylborite, 50 Fluoborite; 55 Shabynite, 55 Wightmanite; 60 Gaudefroyite, 65 Sakhaite, 70 Harkerite; 75 IMA2008-060, 75 Pertsevite; 80 Jacquesdietrichite, 85 Painite
  • 06.AC B(O,OH)₄, without and with additional anions; 1(T), 1(T)+OH, etc.: 05 Sinhalite, 10 Pseudosinhalite; 15 Behierite, 15 Schiavinatoite; 20 Frolovite, 25 Hexahydroborite, 30 Henmilite, 35 Bandylite, 40 Teepleite, 45 Moydite-(Y), 50 Carboborite, 55 Sulfoborite, 60 Luneburgite, 65 Seamanite, 70 Cahnite
• 06.H Unclassified Borates
  • 06.HA Unclassified borates: 05 Chelkarite, 10 Braitschite-(Ce), 15 Satimolite, 20 Iquiqueite, 25 Wardsmithite, 30 Korzhinskite, 35 Halurgite, 40 Ekaterinite, 45 Vitimite, 50 Canavesite, 55 Qilianshanite

Subclass: nesoborates

Main category: Nesoborates

• 06.BA Neso-diborates with double triangles B₂(O,OH)₅; 2(2D); 2(2D) + OH, etc.: 05 Suanite; 10 Clinokurchatovite, 10 Kurchatovite; 15 Sussexite, 15 Szaibelyite; 20 Wiserite
• 06.BB Neso-diborates with double tetrahedra B₂O(OH)₆; 2(2T): 05 Pinnoite, 10 Pentahydroborite
• 06.CA Neso-triborates: 10 Ameghinite, 15 Inderite, 20 Kurnakovite, 25 Inderborite, 30 Meyerhofferite, 35 Inyoite, 40 Solongoite, 45 Peprossiite-(Ce), 50 Nifontovite, 55 Olshanskyite
• 06.DA Neso-tetraborates: 10 Borax, 15 Tincalconite, 20 Hungchaoite; 25 Fedorovskite, 25 Roweite; 30 Hydrochlorborite, 35 Uralborite; 40 Numanoite, 40 Borcarite, 60 Fontarnauite
• 06.EA Neso-pentaborates: 05 Sborgite; 10 Ramanite-(Rb), 10 Ramanite-(Cs), 10 Santite; 15 Ammonioborite, 25 Ulexite
• 06.FA Neso-hexaborates: 05 Aksaite, 10 Mcallisterite, 15 Admontite, 20 Rivadavite, 25 Teruggite

Subclass: inoborates

Main category: Inoborates

• 06.BC Ino-diborates with triangles and/or tetrahedra: 10 Calciborite, 10 Aldzhanite*; 15 Vimsite; 20 Sibirskite, 20 Parasibirskite
• 06.CB Ino-triborates: 10 Colemanite, 15 Hydroboracite, 20 Howlite, 25 Jarandolite
• 06.DB Ino-tetraborates: 05 Kernite
• 06.EB Ino-pentaborates: 05 Larderellite, 10 Ezcurrite, 15 Probertite, 20 Tertschite, 25 Priceite
• 06.FB Ino-hexaborates: 05 Aristarainite, 10 Kaliborite

Subclass: phylloborates

Main category: Phylloborates

• 06.CC Phyllo-triborates: 05 Johachidolite
• 06.EC Phyllo-pentaborates: 05 Biringuccite, 05 Nasinite; 10 Gowerite; 15 Veatchite, 15 Veatchite-A, 15 Veatchite-p; 20 Volkovskite, 25 Tuzlaite, 30 Heidornite, 35 Brianroulstonite
• 06.FC Phyllo-hexaborates: 05 Nobleite, 05 Tunellite, 05 Balavinskite?; 10 Strontioborite; 15 Ginorite, 15 Strontioginorite; 20 Fabianite
• 06.GB Phyllo-nonborates, etc.: 05 Studenitsite, 10 Penobsquisite, 15 Preobrazhenskite, 20 Walkerite

Subclass: tektoborates

Main category: Tektoborates

• 06.BD Tektodiborates with tetrahedra: 05 Santarosaite
• 06.DD Tekto-tetraborates: 05 Diomignite
• 06.ED Tekto-pentaborates: 05 IMA2007-047, 05 Tyretskite, 05 Hilgardite, 05 Kurgantaite
• 06.GA Tekto-heptaborates: 05 Boracite, 05 Chambersite, 05 Ericaite; 10 Congolite, 10 Trembathite
• 06.GC Tekto-dodecaborates: 05 Rhodizite, 05 Londonite
• 06.GD Mega-tektoborates: 05 Ruitenbergite, 05 Pringleite; 10 Metaborite

See also

• Classification of minerals - Non-silicates
• Classification of minerals - Silicates

References

• Hr. Dr. Udo Neumann der Uni-Tuebingen (Systematik der Minerale)

External links

Media related to at Wikimedia Commons