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Unnamed (Magnesium (Iron Calcium) Trisilicate)
Valid as an unnamed mineral
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Formula:
(Mg,Fe,Ca)4Si3O10
structural formula: (Mg,Fe,Ca,Si,◻)2SiO4
Crystal System:
Tetragonal
An UHP shock-related spinelloid phase. Possibly a member of the oxyspinel group (more specifically: the ulvöspinel subgroup).
As irregular to subhedral crystals, ca. 1-3 microns in diameter, in a melt pocket surrounded by ahrensite, bridgmanite and wüstite.
Corresponds to a HT-HP vacancy-stabilized silicate spinel of the ringwoodite-Q-II type; structurally related to ringwoodite-Q and ahrensite-Q.
The composition is derived from 50% olivine (forsterite) and 50% pyroxene molecules.
As irregular to subhedral crystals, ca. 1-3 microns in diameter, in a melt pocket surrounded by ahrensite, bridgmanite and wüstite.
Corresponds to a HT-HP vacancy-stabilized silicate spinel of the ringwoodite-Q-II type; structurally related to ringwoodite-Q and ahrensite-Q.
The composition is derived from 50% olivine (forsterite) and 50% pyroxene molecules.
Unique Identifiers
Mindat ID:
470822
Long-form identifier:
mindat:1:1:470822:9
IMA Classification of Unnamed (Magnesium (Iron Calcium) Trisilicate)
IMA status notes:
Unnamed (probably valid)
Chemistry of Unnamed (Magnesium (Iron Calcium) Trisilicate)
Mindat Formula:
(Mg,Fe,Ca)4Si3O10
structural formula: (Mg,Fe,Ca,Si,◻)2SiO4
structural formula: (Mg,Fe,Ca,Si,◻)2SiO4
Element Weights:
Chemical Analysis
Oxide wt%:
| 1 | |
|---|---|
| SiO2 | 43.68 % |
| FeO | 28.07 % |
| MgO | 17.44 % |
| CaO | 6.40 % |
| Al2O3 | 3.03 % |
| MnO | 0.62 % |
| Na2O | 0.50 % |
| TiO2 | 0.28 % |
| Cr2O3 | 0.25 % |
| Total | 100.26 % |
| Total: | 200.53 % |
Empirical formulas:
| Sample ID | Empirical Formula |
|---|---|
| 1 | (Mg1.72Fe1.56Ca0.45Na0.06Mn0.03Cr0.01Ti0.01)(Si2.90Al0.24Ti0.01)O10 |
Sample references:
| ID | Locality | Reference | Notes |
|---|---|---|---|
| 1 | Tissint Martian meteorite, Tata Cercle, Tata Province, Souss-Massa Region, Morocco | by EPMA-WDS; empirical formula basis: 10 oxygen apfu |
Crystallography of Unnamed (Magnesium (Iron Calcium) Trisilicate)
Crystal System:
Tetragonal
Class (H-M):
4/mmm(4/m2/m2/m) - Ditetragonal Dipyramidal
Space Group:
I41/amd
Cell Parameters:
a = 5.92 Å, c = 8.34 Å
Ratio:
a:c = 1 : 1.409
Unit Cell V:
292.29 ų (Calculated from Unit Cell)
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 Unnamed (Magnesium (Iron Calcium) Trisilicate)
mindat.org URL:
https://www.mindat.org/min-470822.html
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References for Unnamed (Magnesium (Iron Calcium) Trisilicate)
Localities for Unnamed (Magnesium (Iron Calcium) Trisilicate)
Showing 1 localities.
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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.
Morocco | |
| Ma (2023) |
