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Chambersite

A valid IMA mineral species
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About ChambersiteHide

Formula:
Mn2+3(B7O13)Cl
Colour:
Colorless to deep purple
Lustre:
Vitreous
Hardness:
7
Specific Gravity:
3.49
Crystal System:
Orthorhombic
Member of:
Name:
From Chambers County, Texas, USA, where it was first discovered.
Boracite Group. The manganese analogue of Boracite and Ericaite.




Unique IdentifiersHide

Mindat ID:
966
Long-form identifier:
mindat:1:1:966:3

IMA Classification of ChambersiteHide

Approved
IMA Formula:
Mn2+3B7O13Cl
First published:
1962

Classification of ChambersiteHide

6.GA.05

6 : BORATES
G : Heptaborates and other megaborates
A : Tekto-heptaborates
25.6.1.3

25 : ANHYDROUS BORATES CONTAINING HYDROXYL OR HALOGEN
6 : Hexaborates
10.1.18

10 : Borates with other anions
1 : Borates with halide

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
CbsIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Pronunciation of ChambersiteHide

Pronunciation:
PlayRecorded byCountry
Jolyon RalphUnited Kingdom

Physical Properties of ChambersiteHide

Vitreous
Transparency:
Transparent, Opaque
Colour:
Colorless to deep purple
Comment:
Darkens with exposure to sunlight
Hardness:
Fracture:
Irregular/Uneven, Sub-Conchoidal
Density:
3.49(2) g/cm3 (Measured)    3.48 g/cm3 (Calculated)

Optical Data of ChambersiteHide

Type:
Biaxial (+)
RI values:
nα = 1.732 nβ = 1.737 nγ = 1.744
2V:
Measured: 83° , Calculated: 82°
Max. Birefringence:
δ = 0.012
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.

Surface Relief:
Moderate
Dispersion:
r > v

Chemistry of ChambersiteHide

Mindat Formula:
Mn2+3(B7O13)Cl
Element Weights:
Element% weight
O42.979 %
Mn34.057 %
B15.638 %
Cl7.326 %

Calculated from ideal end-member formula.

Crystallography of ChambersiteHide

Crystal System:
Orthorhombic
Class (H-M):
mm2 - Pyramidal
Space Group:
Pca21
Cell Parameters:
a = 8.68(1) Å, b = 8.68(1) Å, c = 12.26(1) Å
Ratio:
a:b:c = 1 : 1 : 1.412
Unit Cell V:
923.70 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Pseudotetrahedral
Twinning:
Rare interpenetrant on [111] with twin plane of {111}

Crystal StructureHide

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IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0011067ChambersiteKubel F, Crottaz O (1996) Crystal structure of manganese chlorine boracite, Mn3B7O13Cl Zeitschrift fur Kristallographie 211 924-9241996synthetic0293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
3.07 Å(100)
2.74 Å(60)
2.08 Å(60)
3.54 Å(50)
2.17 Å(50)
1.851 Å(50)
2.50 Å(30)

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Near-surface Processes
25 : Evaporites (prebiotic)

Type Occurrence of ChambersiteHide

General Appearance of Type Material:
Subhedral to euhedral crystals ranging from less than 1 mm to 1.2 cm on an edge. The dominant form is the positive tetrahedron.
Place of Conservation of Type Material:
Harvard University, Cambridge, Massachusetts, USA, number 107884.
National Museum of Natural History, Washington, D.C., USA, number 115327.
Geological Setting of Type Material:
Saltdome caprock.
Associated Minerals at Type Locality:

Other Language Names for ChambersiteHide

German:Chambersit
Simplified Chinese:锰方硼石
Spanish:Chambersita

Relationship of Chambersite to other SpeciesHide

Member of:
Other Members of Boracite Group:
BoraciteMg3(B7O13)ClOrth. mm2 : Pca21
CongoliteFe2+3B7O13ClTrig. 3m : R3c
EricaiteFe2+3(B7O13)ClOrth. mm2 : Pca21
TrembathiteMg3B7O13ClTrig. 3m : R3c

Related Minerals - Strunz-mindat GroupingHide

6.GA.05EricaiteFe2+3(B7O13)ClOrth. mm2 : Pca21
6.GA.05BoraciteMg3(B7O13)ClOrth. mm2 : Pca21
6.GA.10CongoliteFe2+3B7O13ClTrig. 3m : R3c
6.GA.10TrembathiteMg3B7O13ClTrig. 3m : R3c
6.GA.30KorzhinskiteCa(B2O4) · H2OMon. 2/m : P2/m

Other InformationHide

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 ChambersiteHide

References for ChambersiteHide

Reference List:

Localities for ChambersiteHide

Showing 13 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
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Locality ListHide

- 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). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Canada
 
  • New Brunswick
    • Kings Co.
      • Cardwell Parish
Grice et al. (2005)
Grice (2002)
  • Nova Scotia
    • Cumberland Co.
      • Pugwash
Fundy Geological Museum specimen
China
 
  • Beijing
    • Pinggu District
wrgis.wr.usgs.gov (2004)
  • Hebei
    • Chengde
      • Xinglong County
Xiong Song (1989)
    • Zhangjiakou
      • Zhuolu County
Xiong Song (1989)
  • Tianjin
    • Jizhou
Xiong Song (1989) +2 other references
Madagascar
 
  • Vakinankaratra
    • Betafo District
      • Anosiarivo Manapa
        • Antsentsindrano
Laurs et al. (Skip)
USA
 
  • Louisiana
    • Ascension Parish
      • Darrow
Smith (1994)
    • Plaquemines Parish
Smith (1994)
Smith (1994)
  • Texas
    • Chambers County
      • Mont Belvieu
        • Barbers Hill Salt Dome (Barbers Hill)
Beck (1962)
Beck (1962)
 
and/or  
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