Oxy-schorl from
Cigana claim, Barra do Cuieté, Conselheiro Pena, Minas Gerais, Brazil
| Locality type: | Claim | |
| Classification | ||
|---|---|---|
| Species: | Oxy-schorl | |
| Formula: | Na(Fe22+Al)Al6(Si6O18)(BO3)3(OH)3O | |
| Comments: | In thin section, occurs as pleochroic greenish-blue masses with tavorite, triphylite and other phosphates. Analyzed by EPMA; B estimated from stoichiometry. Permissible Fe3+/∑Fe ranges from 0.000 to 0.115 (i.e. "Z"-site oxygen from 0.45 to maximum 1.00 apfu). Sufficient Al is already present in the "D"-site that any estimated Fe3+/∑Fe value between 0.03 and 0.115 yields "Z"-site oxygen > 0.50 apfu, corresponding to an oxy-schorl composition. Note that "Z"-site and "D"-site are mindat-specific site designations. | |
| Colour: | medium to deep greenish-blue in thin section; presumably black or near black in bulk hand sample. | |
| Confirmation | ||
| Validity: | Believed Valid | |
| Data | ||
| Mineral Data: | Click here to view Oxy-schorl data | |
| Locality Data: | Click here to view Cigana claim, Barra do Cuieté, Conselheiro Pena, Minas Gerais, Brazil | |
| Data Identifiers | ||
| Mindat Occurrence Record ID: | 1591162 | |
| Long-form Identifier: | 1:3:1591162:1 | |
| GUID (UUID V4): | 733c3cf6-3202-4ac4-958b-e277f8e5230f | |
| References | ||
Frank K. Mazdab collectionsample FKM-436; https://www.rockptx.com/fkm-426-to-fkm-450/#FKM-436 | ||
