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 B2 O5 , B3 O6 , B2 O4 anions as well as more complex structures which include hydroxide or halogen anions.[2] The [B(O,OH)4 ]− anion exists as well.
Large (up to 1.8 cm) yellow londonite crystals associated with rubellite tourmaline. Londonite is an unusual caesium -rich heptaborate.[1]
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:
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 νῆσος nêsos , "island")
soro- : grouped (from Greek σωρός sōrós , "heap, pile, mound")
cyclo- : rings of (from Greek κύκλος kúklos , "circle")
ino- : chained (from Greek ίνα ína , "fibre", [from Ancient Greek ἴς ])
phyllo- : sheets of (from Greek φῠ́λλον phúllon , "leaf")
tekto- : three-dimensional framework (from Greek τεκτον ικός tektōnikós , "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 B2 O(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
Subclass: 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-nonaborates, etc.: 05 Studenitsite ; 10 Penobsquisite ; 15 Preobrazhenskite ; 20 Walkerite
Subclass: 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
Klein, Cornelis and Cornelius Hurlbut, Jr., Manual of Mineralogy , Wiley, 20th ed., 1985 pp. 343 - 347 ISBN 0-471-80580-7