Carboborite
A valid IMA mineral species
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About Carboborite
Formula:
Ca2Mg[B(OH)4]2(CO3)2 · 4H2O
Colour:
Colorless
Lustre:
Vitreous
Hardness:
2
Specific Gravity:
2.12
Crystal System:
Monoclinic
Name:
Named in allusion to the composition, containing the essential anionic chemical components, CARBOnate and BORate.
This mineral has been reported from an undisclosed salt lake on the Qinghai-Tibet plateau (Xie et al., 1964), a huge area that includes northern Tibet and northwestern Qinghai provinces. According to Yang (1991), Da Qaidam salt lake in Qinghai Province is the only occurrence of the mineral in that area.
Unique Identifiers
Mindat ID:
891
Long-form identifier:
mindat:1:1:891:0
IMA Classification of Carboborite
Approved
IMA Formula:
Ca2Mg[B(OH)4]2(CO3)2·4H2O
First published:
1964
Classification of Carboborite
6.AC.50
6 : BORATES
A : Monoborates
C : B(O,OH)4, without and with additional anions; 1(T), 1(T)+OH, etc
6 : BORATES
A : Monoborates
C : B(O,OH)4, without and with additional anions; 1(T), 1(T)+OH, etc
27.1.1.1
27 : COMPOUND BORATES
1 : Miscellaneous
27 : COMPOUND BORATES
1 : Miscellaneous
10.4.2
10 : Borates with other anions
4 : Borates with carbonate
10 : Borates with other anions
4 : Borates with carbonate
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Cab | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Carboborite
Vitreous
Transparency:
Translucent
Colour:
Colorless
Hardness:
2 on Mohs scale
Cleavage:
Perfect
{101}, perfect; {110}, distinct; {001}, imperfect.
{101}, perfect; {110}, distinct; {001}, imperfect.
Density:
2.12 g/cm3 (Measured) 2.15 g/cm3 (Calculated)
Optical Data of Carboborite
Type:
Biaxial (-)
RI values:
nα = 1.5069 nβ = 1.5459 nγ = 1.5693
2V:
Measured: 75°
Max. Birefringence:
δ = 0.062
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate
Dispersion:
none
Optical Extinction:
Y = b; X ∧ a = 10°19′; Z ∧ c = 12°.
Chemistry of Carboborite
Mindat Formula:
Ca2Mg[B(OH)4]2(CO3)2 · 4H2O
Element Weights:
Crystallography of Carboborite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 18.59 Å, b = 6.68 Å, c = 11.32 Å
β = 91.68°
β = 91.68°
Ratio:
a:b:c = 2.783 : 1 : 1.695
Unit Cell V:
1,405.13 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Steep pseudorhombohedral crystals, with dominant {101} and {110}, modified by {011}, {110}, {111}, and {101}.
Comment:
Space Group: P21/n.
Crystal Structure
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0012074 | Carboborite | Zhesheng M, Nicheng S, Jinchuan S, Zhizhong P (1981) The refinement of the crystal structure of carboborite MgCa2[CO3]2[B(OH)4]2*4H2O Bulletin de Mineralogie 104 578-581 | 1981 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.63 Å | (100) |
| 4.315 Å | (100) |
| 3.136 Å | (80) |
| 2.160 Å | (80) |
| 2.727 Å | (70) |
| 2.437 Å | (60) |
| 4.86 Å | (50) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 25 : Evaporites (prebiotic) |
Type Occurrence of Carboborite
General Appearance of Type Material:
Steep pseudorhombohedral crystals, 0.5 to 3 mm.
Place of Conservation of Type Material:
National Museum for Geology, Beijing, China, number M05552.
Geological Setting of Type Material:
In a lacustrine borate deposit.
Associated Minerals at Type Locality:
Other Language Names for Carboborite
Dutch:Carboboriet
German:Carboborit
Russian:Карбоборит
Simplified Chinese:水碳硼石
Spanish:Carboborita
Traditional Chinese:水碳硼石
Related Minerals - Strunz-mindat Grouping
| 6.AC.05 | Sinhalite | MgAl(BO4) |
| 6.AC.10 | Pseudosinhalite | Mg2Al3(BO3)2(OH)O3 |
| 6.AC.15 | Béhierite | Ta(BO4) |
| 6.AC.15 | Schiavinatoite | Nb(BO4) |
| 6.AC.20 | Frolovite | Ca[B(OH)4]2 |
| 6.AC.25 | Hexahydroborite | Ca[B(OH)4]2 · 2H2O or CaB2O4 · 6H2O |
| 6.AC.30 | Henmilite | Ca2Cu[B(OH)4]2(OH)4 |
| 6.AC.35 | Bandylite | Cu[B(OH)4]Cl |
| 6.AC.40 | Teepleite | Na2[B(OH)4]Cl |
| 6.AC.45 | Moydite-(Y) | Y[B(OH)4](CO3) |
| 6.AC.55 | Sulfoborite | Mg3[B(OH)4]2(SO4)(OH,F)2 |
| 6.AC.60 | Lüneburgite | Mg3[B2(OH)6](PO4)2 · 6H2O |
| 6.AC.65 | Seamanite | Mn2+3[B(OH)4](PO4)(OH)2 |
| 6.AC.70 | Cahnite | Ca2[B(OH)4](AsO4) |
Fluorescence of Carboborite
Fluoresces white under UV; pale green phosphorescence.
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Carboborite
mindat.org URL:
https://www.mindat.org/min-891.html
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References for Carboborite
Localities for Carboborite
Showing 6 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
China (TL) | |
| Xiande Xie et al. (1964) +3 other references |
| Mineralogical Society of America - ... |
| Mineralogical Society of America - ... | |
Russia | |
| Tony Nikischer and Luis Menezes |
USA | |
| McAllister (1970) +2 other references |
| USGS |
Quick NavTopAbout CarboboriteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
Titovskoe B deposit, Tas-Khayakhtakh Range, Dogdo River Basin, Polar Yakutia, Sakha, Russia