Traskite
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
About Traskite
John Boardman Trask
Formula:
Ba21Ca(Fe2+,Mn,Ti)4(Ti,Fe,Mg)12(Si12O36)(Si2O7)6(O,OH)30Cl6 · 14H2O
Colour:
Red-brown
Lustre:
Vitreous
Hardness:
5
Specific Gravity:
3.71
Crystal System:
Hexagonal
Name:
Named in honor of John Boardman Trask (27 May 1824, Roxbury, Massachusetts, USA - 3 Jul 1879, San Francisco, California, USA), physician and the first state geologist of California.
This page provides mineralogical data about Traskite.
Unique Identifiers
Mindat ID:
4007
Long-form identifier:
mindat:1:1:4007:1
Similar Names
| Terskite | A valid IMA mineral species | Na4ZrSi6O16 · 2H2O |
IMA Classification of Traskite
Approved
IMA Formula:
Ba21Ca(Fe2+,Mn2+,Ti4+)4(Ti4+,Fe2+,Mg)12(Si12O36)(Si2O7)6(O,OH)30Cl6·14H2O
Approval year:
1964
First published:
1965
Classification of Traskite
9.CP.05
9 : SILICATES (Germanates)
C : Cyclosilicates
P : 12-membered and larger rings
9 : SILICATES (Germanates)
C : Cyclosilicates
P : 12-membered and larger rings
64.5.1.1
64 : CYCLOSILICATES Rings with Other Anions and Insular Silicate Groups
5 : Rings with Other Anions and Insular Silicate Groups: 12-membered rings with [Si2O7] dimers
64 : CYCLOSILICATES Rings with Other Anions and Insular Silicate Groups
5 : Rings with Other Anions and Insular Silicate Groups: 12-membered rings with [Si2O7] dimers
17.3.17
17 : Silicates Containing other Anions
3 : Silicates with chloride (including aluminosilicates)
17 : Silicates Containing other Anions
3 : Silicates with chloride (including aluminosilicates)
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 |
|---|---|---|
| Tsk | 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 Traskite
Vitreous
Transparency:
Transparent
Colour:
Red-brown
Streak:
Light red-brown
Hardness:
5 on Mohs scale
Cleavage:
None Observed
Fracture:
Conchoidal
Density:
3.71(2) g/cm3 (Measured) 3.75 g/cm3 (Calculated)
Optical Data of Traskite
Type:
Uniaxial (-)
RI values:
nω = 1.714(3) nε = 1.702(3)
Max. Birefringence:
δ = 0.012
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:
Visible
Comments:
O = brownish red; E = colorless or straw-yellow
Chemistry of Traskite
Mindat Formula:
Ba21Ca(Fe2+,Mn,Ti)4(Ti,Fe,Mg)12(Si12O36)(Si2O7)6(O,OH)30Cl6 · 14H2O
Element Weights:
Common Impurities:
Al,Mn,Mg,Ca,Sr,K
Crystallography of Traskite
Crystal System:
Hexagonal
Class (H-M):
6m2 - Ditrigonal Dipyramidal
Space Group:
P6m2
Cell Parameters:
a = 17.89(1) Å, c = 12.33(1) Å
Ratio:
a:c = 1 : 0.689
Unit Cell V:
3,417.55 ų (Calculated from Unit Cell)
Z:
3
Morphology:
Generally anhedral grains. Euhedral crystals show the forms {0001} and {1010} prominently, but many tiny pyramid faces occur on some crystals. Tentative forms include {ll22}, (4152), and (6171).
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) |
|---|---|---|---|---|---|---|---|
| 0012455 | Traskite | Malinovskii Yu A, Pobedimskaya E A, Belov N V (1976) Crystal structure of traskite Doklady Akademii Nauk SSSR 229 1101-1104 | 1976 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.96 Å | (100) |
| 15.4 Å | (50) |
| 3.51 Å | (40) |
| 3.08 Å | (35) |
| 3.27 Å | (25) |
| 2.90 Å | (25) |
| 3.21 Å | (20) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits |
Type Occurrence of Traskite
Place of Conservation of Type Material:
California Division of Mines & Geology, San Francisco, California, USA.
Synonyms of Traskite
Other Language Names for Traskite
Common Associates
Associations Based on Photo Data:
| 7 photos of Traskite associated with Sanbornite | BaSi2O5 |
| 4 photos of Traskite associated with Quartz | SiO2 |
| 3 photos of Traskite associated with Pyrrhotite | Fe1-xS |
| 2 photos of Traskite associated with Kampfite | Ba12(Si11Al5)O31(CO3)8Cl5 |
| 1 photo of Traskite associated with Fresnoite | Ba2Ti(Si2O7)O |
Related Minerals - Strunz-mindat Grouping
| 9.CP.10 | Megacyclite | Na8KSi9O18(OH)9 · 19H2O |
| 9.CP.15 | Laurentianite | Na3Nb3Si4O17 · 9H2O |
Fluorescence of Traskite
None observed.
Other Information
Thermal Behaviour:
Gives off water in a closed tube test.
Rapidly heated to 900 °C in an electric furnace, the mineral turns light brown. At 1200 °C the mineral melts completely to a straw yellow glass.
Rapidly heated to 900 °C in an electric furnace, the mineral turns light brown. At 1200 °C the mineral melts completely to a straw yellow glass.
Notes:
Insoluble in dilute acids and bases. On prolonged standing in dilute hydrochloric acid, the mineral turns almost opaque brown and loses its glassy appearance.
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 Traskite
mindat.org URL:
https://www.mindat.org/min-4007.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 Traskite
Reference List:
Alfors, John T., Stinson, Melvin C., Matthews, Robert A., Pabst, Adolf (1965) Seven new barium minerals from eastern Fresno County, California. American Mineralogist, 50 (3-4) 314-340
Alfors, John T., Putman, George W. (1965) Revised chemical analyses of traskite, verplanckite, and muirite from Fresno County, California. American Mineralogist, 50 (9) 1500-1503
Localities for Traskite
Showing 5 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.
Slovakia | |
| Koděra |
USA | |
| Walstrom (n.d.) |
| Walstrom (n.d.) | |
| Walstrom (n.d.) +2 other references |
| Walstrom (n.d.) |
Quick NavTopAbout TraskiteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
Snow Cap Mine, Rush Creek, Big Creek-Rush Creek Mining District, Fresno County, California, USA