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Braunite-II from
N'Chwaning II Mine, N'Chwaning Mines, Joe Morolong Local Municipality, John Taolo Gaetsewe District Municipality, Northern Cape, South Africa
| Locality type: | Mine | |
| Classification | ||
|---|---|---|
| Species: | 'Braunite-II' (not an IMA approved species) | |
| Formula: | Ca(Mn3+,Fe)14(SiO4)O20 | |
| Comments: | Braunite II was first discovered in 1945 at Black Rock and described as ferrianbraunite. The phase was renamed braunite II by De Villiers and Herbstein in 1967 and its crystal structure was determined by De Villiers in 1980. Metallic-grey braunite II crystals have come from Wessels, Black Rock (up to two centimetres) and N’Chwaning II. The crystals are typically bipyramidal with complex terminations. In 1995, crystals up to three centimetres were found at Wessels mine, and a few very rare larger crystals were also collected at the time. These were associated with andradite garnet, hausmannite and occasionally yellow ettringite. Braunite II is not listed as a recognised species in the IMA RRUFF database. See De Villiers (1945), De Villiers and Herbstein (1967), De Villiers (1970), De Villiers (1980) and De Villiers (1989) for details. | |
| Confirmation | ||
| Validity: | Believed Valid | |
| Associated Minerals Based on Photo Data: | ||
| Andradite | 9 | |
| Hausmannite | 4 | |
| Baryte | 2 | |
| Calcite | 2 | |
| Despujolsite | 2 | |
| Clinochlore | 2 | |
| Ettringite | 1 | |
| Bixbyite-(Mn) | 1 | |
| Data | ||
| Mineral Data: | Click here to view Braunite-II data | |
| Locality Data: | Click here to view N'Chwaning II Mine, N'Chwaning Mines, Joe Morolong Local Municipality, John Taolo Gaetsewe District Municipality, Northern Cape, South Africa | |
| Photo Gallery | View Gallery (8 photos) | |
| Data Identifiers | ||
| Mindat Occurrence Record ID: | 719338 | |
| Long-form Identifier: | 1:3:719338:5 | |
| GUID (UUID V4): | 0 | |
| Nearest other occurrences of Braunite-II | ||
| 2.7km (1.7 miles) | ⓘWessels Mine, Joe Morolong Local Municipality, John Taolo Gaetsewe District Municipality, Northern Cape, South Africa | |
| 3.1km (1.9 miles) | ⓘBlack Rock Mine, Black Rock, Joe Morolong Local Municipality, John Taolo Gaetsewe District Municipality, Northern Cape, South Africa | |
| References | ||
de Villiers, P. R., Herbstein, F. H. (1967) Distinction between two members of the braunite group. American Mineralogist, 52 (1-2) 20-30 de Villiers, Johan P. R. (1980) The crystal structure of braunite II and its relation to bixbyite and braunite. American Mineralogist, 65 (7-8) 756-765 | ||
N'Chwaning II Mine, N'Chwaning Mines, Joe Morolong Local Municipality, John Taolo Gaetsewe District Municipality, Northern Cape, South Africa