|
Tourmaline
Unlike
amethyst and topaz, tourmaline has escaped inordinate exploitation on
the Brazilian market, probably because it is rarer and consequently
more expensive. It is a mineral group of varying composition occurring
in different colours, especially green, blue and grey. Pink specimens
are known as rubellite.
Tourmaline has a deep brilliance and rich colouring. Transparent
specimens being quite common, the stone is either cut en cabochon or
faceted. Specimens with inclusions are used for beads.
Green tourmaline should not be confused with emerald, or red
tourmaline with ruby. It has a wide distribution and is especially
diffuse in Brazil and Madagascar.
|
Name |
|
|
|
|
|
|
|
|
|
| Tourmaline |
7+ |
3.02-3.26 |
Hexagonal
|
None
|
1.616-1.652
|
-0.014
-0.044 |
0.017
|
Definite to
strong |
Weak |
|
