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 as well.
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)2·3H2O Borax Na2B4O5(OH)4·8H2O Ulexite NaCaB5O6(OH)6·5H2O Colemanite CaB3O4(OH)3·H2O Boracite Mg3B7O13Cl Painite CaZrAl9O15(BO3)
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). Note that although Nickel–Strunz division letters were traditionally based on the number of boron atoms in a mineral's chemical formula (06.A are monoborates, 06.B are diborates, etc.), the IMA has reclassified borate minerals based on the polymerisation of the borate anion.
Abbreviations
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) * : discredited (IMA/CNMNC status) ? : questionable/doubtful (IMA/CNMNC status) Regarding 03.C Aluminofluorides, 06 Borates, 08 Vanadates (04.H V[5,6] Vanadates), 09 Silicates: neso-: insular (from Greek , "island") soro-: grouped (from Greek , "heap, pile, mound") cyclo-: rings of (from Greek , "circle") ino-: chained (from Greek , "fibre", [from Ancient Greek ]) phyllo-: sheets of (from Greek , "leaf") tekto-: three-dimensional framework (from Greek , "of building") 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 an 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 Béhierite, 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
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
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