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Chromdravite Mineral Data
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General Chromdravite Information
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 Chemical Formula: |
NaMg3(Cr,Fe+++)6(BO3)3Si6O18(OH)4 |
| Composition: |
Molecular Weight = 1,114.61 gm |
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Sodium 2.06 % Na 2.78 % Na2O |
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Magnesium 6.54 % Mg 10.85 % MgO |
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Chromium 20.99 % Cr 27.45 % CrO |
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Iron 7.52 % Fe 10.75 % Fe2O3 |
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Silicon 15.12 % Si 32.34 % SiO2 |
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Boron 2.91 % B 9.37 % B2O3 |
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Hydrogen 0.36 % H 3.23 % H2O |
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Oxygen 44.50 % O |
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______ ______ |
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100.00 % 96.77 % = TOTAL OXIDE |
| Empirical Formula: |
NaMg3Cr4.5Fe3+1.5(BO3)3Si6O18(OH)4 |
| Environment: |
Magnesium and chromium-bearing tourmaline in micaceous metasomatites. |
| IMA Status: |
Approved IMA 1983 (Dana # Changed) |
| Locality: |
Onezhkii depression, central Karelia, Russia. Link to MinDat.org Location Data. |
| Name Origin: |
Named for the compositional relationship to dravite. |
| Synonym: |
Chromdravite - (61.3.1.11) |
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Tourmaline |
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