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Chemical formula
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(Na,Ca)(Al,Fe,Li)(Al,Mg,Mn) 6 (BO 3 ) 3 (Si 6 O 18 ).(OH,F) 4 |
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Crystalline system
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trigonal, hexagonal |
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Class
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silicates |
| Origin | Minas Gerais, Brazil |
| Size |
Medium : 3.0-4.0 cm Large : 4.0-5.0cm |
Radial black tourmaline in various sizes.
Black tourmaline is a mineral found in different forms. It is possible to find it in pegmatites, granites, seams, hydrothermals and micaceous schists. It also occurs in alpine crevasses.
The piece you receive may differ slightly from the photo shown as the minerals are natural and no piece is identical. The size is approximate.