How to Buy Tourmaline
No two tourmaline gems are exactly alike, which makes this a one-of-a-kind gift for any individual—especially someone celebrating an October birthday or an eighth wedding anniversary.
With a wide variety of colors, qualities and sources available, there’s tourmaline to suit a range of styles and budgets. Like diamonds, tourmaline is evaluated by the criteria of: color, clarity, cut and carat weight.
In general, darker toned tourmaline that appears black is priced much lower than brightly colored material. Rubellite tourmaline, in shades of pink or red, is one of this gem’s most desirable colors.
Green and blue tourmaline are also popular, though the most striking shades of these colors come from Brazil’s exotic Paraíba tourmaline. At about $10,000 per carat, this is the most valuable variety of tourmaline.
Inclusions are common in tourmaline, because liquids can get trapped as bubbles during crystallization. It’s not uncommon for red or pink tourmaline to display visible inclusions, but inclusions can drastically lower the value of other colors.
Some tourmaline material, especially rubellite, undergoes heat treatment to improve color. Other tourmaline is clarity-enhanced to remove inclusions, which can significantly lower the value.
Because tourmaline forms in slender, columnar crystals, many finished gems have long, irregular shapes.
Tourmalines tend to absorb light down the length of a crystal, rather than across it. This makes these gems “pleochroic,” which means they appear different colors from different directions—so the cut is critical.
Paraíba tourmaline is rare in sizes larger than one carat. But with these stones, color is more highly valued than size, so a small, brightly colored gem is preferred over a large, dark one.
With such a wide range of tourmaline options available—from the common, inexpensive schorl to the highly valued Paraíba—the price of these gems can vary greatly.