It has one of the color ranges in the mineral world. The most common color is black, but tourmaline may be pink, violet-red, brownish yellow, blackish brown, various shades of green, light blue, blue-green, dark blue, and (rarely colorless). Fine crystals with concentric zoning are found; typically they are red on the inside and green on the outside and are known as watermelon tourmalines. Also find are crystals transverse zoning, the color of crystal gradually changing from one end to the other, as in the “Moor’s head” crystals found on the island of Elba. Tourmaline has good resistance to weathering and is therefore often found in alluvium.

Pink to red color tourmaline is called rubillite. The color varies from pink of varying degrees of intensity to a red which is quite attractive, although usually a bit less than that of ruby; it may also be violet pink or red. Tourmalines have strong pleochroism, sometimes visible as a deeper color or lesser transparency along the axis of prism. It is cut in all shapes; cabochons when the stone is too full of inclusions, but more often faceted oval, round, pear-shaped or other creative styles. Quite large stones are often seen. Tourmaline can be rich green, a touch colder than the color of emerald; or leaf green, tending to deep olive green. Mid-to light-color specimens have good luster. Darker stones often look a bit opaque. Many are virtually free of inclusions.



Distinctive features:
The more definite or darker shades are characteristic. Loss of transparency along the stone, particularly in gems that are cut rectangular, is peculiar to tourmaline. Tourmalines are, as a rule, also rather duller than other, similar gems, but may be a beautiful, brilliant violet-pink.



Occurrence:
It is found in Brazil, the United States, Tanzania, Mozambique, Namibia, Siberia, Burma, and Sri Lanka.



Value:
As the rubilite and indicolite, only the lively, mid-colored stones are valuable. When the color is an uncharacteristic pale green, or the most typical dark or olive green, they are worth much less.