Most tourmalines undergo heat and radiation treatments to achieve these hues. However, these procedures have stable results.

With so many varieties and colors, you can always add more tourmalines to your collection.

Tourmaline Buying and the Four Cs

The IGS tourmaline value listing has price guidelines for paraíba tourmalines, indicolite, rubellite, chrome tourmalines, and other colors of faceted stones, as well as cat’s eye and non-phenomenal cabochons.

Color

Tourmalines come in all the colors of the rainbow. When buying tourmaline of any color, view it under several different types of lighting, as most gems will exhibit some alteration in color or decreased saturation in incandescent light.

Blue

In tourmalines, blue and blue-green hues arise from iron or copper in the crystal structure. While rare, blue hues are also the most popular color of this gemstone.

Indicolite is the gemological name for blue tourmalines. Generally, this term refers to tourmalines colored by iron. Indicolites can be greyish blue, blue, or blue-green. The most costly gems exhibit medium tones and saturated color. Since indicolites commonly receive heat and radiation treatments, ask about treatments before purchasing.

If you’re interested in indicolites, read the indicolite buying guide.

Paraíba

In 1989, a new variety…