Colinowensite
A valid IMA mineral species
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About Colinowensite
Colin R. Owen
Formula:
BaCuSi2O6
Colour:
Purple to dark blue (when thicker)
Lustre:
Vitreous
Hardness:
4
Specific Gravity:
4.20
Crystal System:
Tetragonal
Name:
Named in honor of Colin R. Owen (1937 - 26 October 2020), a mineral dealer from Somerset West, South Africa. He provided the first specimens for study.
New structure type.
Found in the Central-Eastern orebody of the Wessel's mine.
Found in the Central-Eastern orebody of the Wessel's mine.
Unique Identifiers
Mindat ID:
43366
Long-form identifier:
mindat:1:1:43366:6
IMA Classification of Colinowensite
Approved
IMA Formula:
BaCu2+Si2O6
Approval year:
2012
First published:
2015
Classification of Colinowensite
9.C0.
9 : SILICATES (Germanates)
C : Cyclosilicates
0 :
9 : SILICATES (Germanates)
C : Cyclosilicates
0 :
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 |
|---|---|---|
| Cwn | 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 Colinowensite
Vitreous
Transparency:
Opaque
Colour:
Purple to dark blue (when thicker)
Streak:
Purple
Hardness:
4 on Mohs scale
Tenacity:
Brittle
Fracture:
Irregular/Uneven
Density:
4.20(5) g/cm3 (Measured) 4.236 g/cm3 (Calculated)
Optical Data of Colinowensite
Type:
Uniaxial (-)
RI values:
nω = 1.740 - 1.745 nε = 1.735(20)
Max. Birefringence:
δ = 0.010
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:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Pleochroism:
Strong
Comments:
Purple along the c axis to blue in a perpendicular direction.
Chemistry of Colinowensite
Mindat Formula:
BaCuSi2O6
Element Weights:
Elements listed:
Crystallography of Colinowensite
Crystal System:
Tetragonal
Class (H-M):
4/mmm(4/m2/m2/m) - Ditetragonal Dipyramidal
Space Group:
I41/acd
Cell Parameters:
a = 9.967(1) Å, c = 22.290(2) Å
Ratio:
a:c = 1 : 2.236
Unit Cell V:
2221.4 ų
Z:
16
Morphology:
{100} and {110}. {001} is always present as cleavage planes.
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
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Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
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2D | Stereo | Red-Blue | Red-Cyan
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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) |
|---|---|---|---|---|---|---|---|
| 0020059 | Colinowensite | Chen Y, Zhang Y, Feng S (2014) Hydrothermal synthesis and properties of pigments Chinese purple BaCuSi2O6 and dark blue BaCu2Si2O7 Dyes and Pigments 105 167-173 | 2014 | synthetic | 0 | 293 | |
| 0018747 | Colinowensite | Sparta K M, Roth G (2004) Reinvestigation of the structure of BaCuSi2O6 - evidence for a phase transition at high temperature Acta Crystallographica B60 491-495 |  | 2004 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.577 Å | (31) |
| 4.997 Å | (30) |
| 4.560 Å | (31) |
| 3.533 Å | (70) |
| 2.985 Å | (100) |
| 2.499 Å | (57) |
| 2.280 Å | (23) |
| 1.767 Å | (19) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 31 : Thermally altered carbonate, phosphate, and iron formations | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits |
Type Occurrence of Colinowensite
General Appearance of Type Material:
Subhedral crystals to 100 × 100 × 50 μm, but most do not exceed 50 μm in any direction.
Place of Conservation of Type Material:
Type material is preserved in the collections of the Institute für Mineralogie und Kristallographie, University of Vienna, Vienna, Austria, catalogue number HS13.097.
Associated Minerals at Type Locality:
Synonyms of Colinowensite
Other Language Names for Colinowensite
Dutch:Colinowensiet
German:Colinowensit
Common Associates
Associations Based on Photo Data:
Fluorescence of Colinowensite
None observed.
Other Information
Notes:
Not soluble in acids except HF.
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 Colinowensite
mindat.org URL:
https://www.mindat.org/min-43366.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 Colinowensite
Reference List:
Finger, L. W., Hazen, R. M., Hemley, R. J. (1989) BaCuSi2O6: A new cyclosilicate with four-membered tetrahedral rings. American Mineralogist, 74 (7-8) 952-955
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2013) IMA Commission on New Minerals, Nomenclature and Classification. CNMNC Newsletter No. 15. Mineralogical Magazine, 77 (1) 1-12 doi:10.1180/minmag.2013.077.1.01
Rieck, B., Pristacz, H., Giester, G. (2015) Colinowensite, BaCuSi2O6, a new mineral from the Kalahari Manganese Field, South Africa and new data on wesselsite, SrCuSi4O10. Mineralogical Magazine, 79 (7) 1769-1778 doi:10.1180/minmag.2015.079.7.04
Localities for Colinowensite
Showing 1 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.
South Africa (TL) | |
| Williams et al. (2013) +1 other reference |
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Wessels Mine, Joe Morolong Local Municipality, John Taolo Gaetsewe District Municipality, Northern Cape, South Africa