Indicolite Buying and the Four Cs

With a hardness of 7 to 7.5 and no cleavage, tourmalines of all types have good durability. However, watch out for stones with flaws/low clarity because these may be weaker.

For more information on general tourmaline quality factors, consult our tourmaline buying guide.

Color

Indicolites can range from light to dark saturated blue. Although color grading is a judgment call, I think many tourmalines sold as blue are misrepresented. In my opinion, an indicolite can be any shade or color as long as blue predominates. For example, most indicolites have some degree of green in them. (See the gem to the right, for example).

I would call a blue/green stone with dominant blue a blue tourmaline. If the green dominates, I’d call it a green tourmaline or verdelite. Generally, blue brings more money, which explains why some in the trade are eager to call blue/green tourmalines indicolites even if the green predominates.

Of course, most tourmalines receive heat treatments, which can remove or lighten any green tones.

What are Paraíba Tourmalines?

The well-known paraíba tourmaline possesses the top color for all blue tourmalines. These copper-bearing stones can show a neon blue.…