Probertite
A valid IMA mineral species - grandfathered
This page is currently not sponsored. Click here to sponsor this page.
About Probertite
Formula:
NaCa[B5O7(OH)4] · 3H2O
Colour:
Colourless, white; colourless in transmitted light
Lustre:
Vitreous
Hardness:
3½
Specific Gravity:
2.135 - 2.141
Crystal System:
Monoclinic
Name:
Named in honor of Frank Holman Probert (13 June 1876, London, England – 7 May 1940, Berkeley, California, USA), Dean of the Mining College, University of California, Berkeley, California, USA, who provided the first specimens.
The structure is based on the pentaborate polyanion, of 5(2Δ + 3T) topology. It comprises oxygen-sharing B-bearing tetrahedra and B-bearing triangular groups. The polyanion comprises 5 geometrical components: BO3, BO2(OH), BO4, BO3(OH), and BO2(OH)2. The polyanions are joined, thus forming chains || [100]. Calcium forms clusters comprising distorted Ca polyhedra, CaO5(OH)3(OH2). Sodium exists as NaO(OH)2(OH2)3 polyhedra, that are connected via edge-sharing. Hydrogen bonding is present, too.
Unique Identifiers
Mindat ID:
3285
Long-form identifier:
mindat:1:1:3285:4
GUID
(UUID V4):
(UUID V4):
3fe625b7-5ed5-4797-b0c5-95d4bdcb816d
IMA Classification of Probertite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
NaCaB5O7(OH)4 · 3H2O
First published:
1929
Type description reference:
Classification of Probertite
6.EB.15
6 : BORATES
E : Pentaborates
B : Ino-pentaborates
6 : BORATES
E : Pentaborates
B : Ino-pentaborates
26.5.12.1
26 : HYDRATED BORATES CONTAINING HYDROXYL OR HALOGEN
5 : Pentaborates
26 : HYDRATED BORATES CONTAINING HYDROXYL OR HALOGEN
5 : Pentaborates
9.3.20
9 : Borates
3 : Borates of Ca and Sr
9 : Borates
3 : Borates of Ca and Sr
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 |
|---|---|---|
| Pbr | 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 Probertite
Vitreous
Transparency:
Transparent, Translucent
Comment:
Satiny
Colour:
Colourless, white; colourless in transmitted light
Streak:
White
Hardness:
3½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
On {110}.
On {110}.
Density:
2.135 - 2.141 g/cm3 (Measured) 2.132 g/cm3 (Calculated)
Optical Data of Probertite
Type:
Biaxial (+)
RI values:
nα = 1.514 - 1.517 nβ = 1.524 nγ = 1.543 - 1.544
2V:
Measured: 73° , Calculated: 74°
Max Birefringence:
δ = 0.029
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
Relatively weak.
Optical Extinction:
Y = b; Z ∧ c = 12°–13°.
Chemistry of Probertite
Mindat Formula:
NaCa[B5O7(OH)4] · 3H2O
Crystallography of Probertite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Setting:
P21/a
Cell Parameters:
a = 13.428(2) Å, b = 12.560(2) Å, c = 6.588(1) Å
β = 99.97(1)°
β = 99.97(1)°
Ratio:
a:b:c = 1.069 : 1 : 0.525
Unit Cell V:
1,094.32 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Crystals aggregated into rosettes or radial groups of needles or laths. Spherulitic; as tough, compactly reticulated aggregates. Single crystals rare. Crystals acicular [001], commonly flattened {100} (slightly to considerably); also flattened {110}, rare. Faces "b," "a," and "m" usually striated [001] and rounded.
Twinning:
Doubtful under the microscope.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
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) |
|---|---|---|---|---|---|---|---|
| 0009784 | Probertite | Menchetti S, Sabelli C, Trosti-Ferroni R (1982) Probertite, CaNa[B5O7(OH)4]*3H2O: a refinement Acta Crystallographica B38 3072-3075 |  | 1982 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Image Loading
Radiation - Copper Kα
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 9.12 Å | (100) |
| 2.807 Å | (35) |
| 6.62 Å | (20) |
| 3.52 Å | (20) |
| 2.935 Å | (20) |
| 2.884 Å | (20) |
| 2.172 Å | (20) |
Comments:
Boron, California, USA. Data from Clark and Christ (1959).
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3b: Earth’s earliest hydrosphere | >4.45 |
| 14 : Hot springs, geysers, and other subaerial geothermal minerals | |
| Near-surface Processes | |
| 25 : Evaporites (prebiotic) |
Type Occurrence of Probertite
General Appearance of Type Material:
Acicular to elongated.
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA, 95832–95833.
Geological Setting of Type Material:
Lake-bed deposits.
Associated Minerals at Type Locality:
Reference:
Eakle, A.S. (1929) Probertite, a new borate. American Mineralogist: 14: 427-430.
Synonyms of Probertite
Other Language Names for Probertite
Common Associates
Associated Minerals Based on Photo Data:
| 6 photos of Probertite associated with Gerstleyite | Na2(Sb,As)8S13 · 2H2O |
| 4 photos of Probertite associated with Ulexite | NaCa[B5O6(OH)6] · 5H2O |
Related Minerals - Strunz-mindat Grouping
| 6.EB.05 | Larderellite | (NH4)B5O7(OH)2 · H2O |
| 6.EB.05 | Yarzhemskiite | K[B5O7(OH)2] · H2O |
| 6.EB.10 | Ezcurrite | Na4B10O17 · 7H2O |
| 6.EB.20 | Tertschite | Ca4B10O19 · 20H2O |
| 6.EB.25 | Priceite | Ca2B5O7(OH)5 · H2O |
Other Information
Notes:
Readily soluble in dilute acids. Partially decomposed in hot or cold water, with Na being leached relative to Ca.
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 Probertite
mindat.org URL:
https://www.mindat.org/min-3285.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Probertite
Reference List:
Foshag, William Frederick (1931) Probertite from Ryan, Inyo County, California. American Mineralogist, 16 (8) 338-341
Barnes, William (1949) The unit cell and space group of probertite. American Mineralogist, 34 (1-2) 19-25
Barnes, William H. (1949) Corrections to recent papers on probertite and lindgrenite. American Mineralogist, 34 (7-8) 611-613
Clark, J. R., Christ, C. L. (1959) Studies of borate minerals (V): Reinvestigation of X-ray crystallography of ulexite and probertite. American Mineralogist, 44 (7-8) 712-719
Menchetti, S., Sabelli, C., Trosti-Ferroni, R. (1982) Probertite, CaNa[B5O7(OH)4]·3H2O: a refinement. Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 38 (12) 3072-3075 doi:10.1107/s0567740882010851
Localities for Probertite
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.
Quick NavTopAbout ProbertiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Kohnstein Quarry, Niedersachswerfen, Harztor, Nordhausen District, Thuringia, Germany