Tourmaline

Tourmaline is found in all colors (white, green, pink, blue, yellow, orange, brown, purple, multi-colored). The most usual colors include black (Schorl), green, pink, and multi-colored. Rare bright or neon blue tourmaline is referred to as Paraiba with other another shade of blue as Indicolite, and most recently red tourmaline has been called Rubellite. Tourmaline is part of the Hexagonal crystal system with a level of 7 – 7.5 on the Mohs hardness scale, a refractive index of 1.65, and specific gravity between 2.9 and 3.3.

Transparent to opaque, crystals are often “closed,” meaning light only travels through one axis of the stone. Tourmaline also forms in a unique color combination know as watermelon with a pink interior and green exterior on the crystal. Watermelon tourmaline is often sliced and used natural in jewelry.

Tourmaline occurs most in pegmatites, but is found in placer or alluvial deposits. Primary finds are from Brazil or Africa (Tanzania, Kenya, Madagascar, Nigeria, Nambia, Malawi, Mozambique). Additional finds of material have been found in Sri Lanka, Russia, Afghanistan, Pakistan, and the United States (California and Maine). Paraiba (blue) tourmaline was first mined in Brazil and is some of the most expensive per ct, sought after by collectors.

At times tourmaline is found with parallel inclusions which causes an effect known as chatoyancy or more commonly as Cat’s Eye. Gems with this effect are usually cut into dome top gems know as cabochons.

Treatment

Thought Tourmaline naturally occurs in excellent colors, the gem is heated at times which can enhance the color. Heat treatment is usually permanent and is a widely accepted treatment not impacting the value of the gemstone.

Tourmaline 8.45 cts