|
Chemical formula
|
(Na,Ca)(Al,Fe,Li)(Al,Mg,Mn) 6 (BO 3 ) 3 (Si 6 O 18 ).(OH,F) 4 |
|
Crystalline system
|
trigonal, hexagonal |
|
Class
|
silicates |
| Origin | Minas Gerais, Brazil |
| Size |
1.5-2.0cm |
Crystallized black tourmaline in trigonal prism.
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 mineral includes a label with the name and origin and is attached to a cardboard box. 4 cm square.
*The price is per unit (a single cardboard box of the four shown in the photo)
Since the minerals are natural, you will receive a piece similar to the one in the photograph. The minerals come in cardboard boxes and are glued to a porex base with hot silicone; these can be removed using ethyl alcohol without damaging the mineral. The size is approximate.