
The tourmaline is an aluminum and alkali borosilicate complex , with iron, magnesium and other cations. Its range of colors is the largest in the mineral world
General Physical properties: hardness from 7 to 7.5 - density from 3.02 to 3.20 g/cm3 - refractive indexes about 1.62 and 1.64 with birefraction rather high
- Weight: 2.22 Kt
- Size 10.60 x 6 x 3.70 mm
- Cut: table and steps with rectangular elongated shape and sharp edges
- Color: intense dark green
- Purity: pure
- Treatments: none
- Origin: Brazil