TOURMALINE


All facts and figures taken from the GIA

TOURMALINE

Tourmalines have a wide variety of exciting colors with one of the widest color ranges of any gem. Tourmaline’s colors have many different causes. It’s generally agreed that traces of iron, and possibly titanium, induce green and blue colors. Manganese produces reds and pinks, and possibly yellows. Some pink and yellow tourmalines might owe their hues to color centers caused by radiation, which can be natural or laboratory-induced.


MINERAL: Tourmaline
CHEMISTRY: Elbaite
Dravite
Liddicoatite
Chromedravite
COLOR: All colors
REFRACTIVE INDEX: 1.624 to 1.644
BIREFRINGENCE: 0.018 to 0.040
SPECIFIC GRAVITY: 3.06 (+0.20, -0.06)
MOHS HARDNESS: 7 to 7.5


Tourmaline is known as being one of the birthstones of the month October.

FOUND WHERE

Precious_Gemstone_Where_Found_Tourmaline