Tourmaline forms in hexagonal prismatic crystals in metamorphic and igneous
rocks and veins. The purplish-red variety, known as Rubellite, is the most
valueable, but perhaps the gem of greatest interest is the so-called Watermelon
Tourmaline with its green and pink crystals. Another variety is known as Indicolite,
owing to its blue tone. First quality gems come from California, Maine, Burma,
and the Malagasy Republic. It is faceted and made into beads and has gained
wide usage as a semiprecious gemstone.
This gem derives its name from the Singhalese word Touramalli, meaning
mixed coloured stones.
