Tourmaline

TOURMALINE

Tourmalines Tourmaline is a varied and versatile gem. It comes in every color, and as with all colored gems the most expensive will be the ones with the brightest colors. Because long tourmaline crystals sometimes show two colors, these shapes will be set into jewelry. Once again, the two colors--their respective vividness and their collective contrast--will determine price.

The most expensive varieties are the green chrome varieties from Tanzania, and the amazing bluish Brazilian stones know as Paraiba tourmalines. Chrome tourmalines rival emeralds in color, and cost almost as much. Paraiba tourmalines are even rarer and more expensive and rank among the most precious of gems, with colors and prices that rival the finest sapphire and tanzanite.

Fine green tourmalines can run close to a thousand dollars a carat, but are more often closer to about half that price. Because they often show an excellent green color, they are a good substitute for more expensive emeralds or tsavorites. Pink tourmalines usually cost even less, depending on color saturation--the preferred colors are bright lemonade pink and a cranberry-red. Tourmalines that are ruby colored are called rubellite tourmalines, and they cost more. There's ample proof that rubellite tourmalines make excellent ruby substitutes--royal families were fooled for centuries.

Most tourmalines are heat treated to improve color. This process is permanent and stable. Tourmalines are also commonly irradiated to improve color. Unlike with some other gems, irradiation is a stable and permanent process with tourmalines. Since tourmalines are not especially prone to inclusions, oil treatments or fracture filling are rare.

Tourmaline rank around 7-7.5 on the Mohs scale of hardness, and can be set in a variety of ways safety. They are less prone to chipping than emeralds or other gems that have more inclusions. Tourmalines can be safely cleaned with warm water and mild soap, but mechanical cleaners should be avoided.