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Brinrobertsite Mineral Data
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General Brinrobertsite Information
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 Chemical Formula: |
(Na,K,Ca)x(Al,Fe,Mg)4(Si,Al)8O20(OH)4•3.54(H2O) [x = 0.35, n = 3.54] |
| Composition: |
Molecular Weight = 957.70 gm |
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Potassium 0.29 % K 0.34 % K2O |
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Sodium 0.53 % Na 0.71 % Na2O |
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Calcium 0.25 % Ca 0.35 % CaO |
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Magnesium 0.20 % Mg 0.34 % MgO |
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Aluminum 11.18 % Al 21.13 % Al2O3 |
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Iron 0.47 % Fe 0.60 % FeO |
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Silicon 22.99 % Si 49.19 % SiO2 |
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Hydrogen 3.06 % H 27.34 % H2O |
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Oxygen 61.03 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
| Empirical Formula: |
Na0.22K0.07Ca0.06Al3.81Mg0.08Fe2+0.08Si7.84Al0.16O20(OH)43.54(H2O)3.54 |
| Environment: |
Found in an Ordovician soapy mudtone (metabentonite). Altered from ash (glass) with pyrophyllite as the precursor mineral. |
| IMA Status: |
Approved IMA 2002 (Dana # Added) |
| Locality: |
Bangor, North Wales, England, Great Britain Link to MinDat.org Location Data. |
| Name Origin: |
Named for Brin Roberts, specialist for British clay minerals in the University of London. |
| Synonym: |
IMA1997-040 |
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