What is the trade term for blue tourmaline?

The trade term for blue tourmaline is "indicolite." This terminology originated from the Greek word "indicos," meaning "indigo," which reflects the color characteristics of this variety of tourmaline. Indicolite is specifically used to describe blue hues of tourmaline that can range from pale blue to deep blue. This distinction is significant within the gem and jewelry industry, as it helps to identify and categorize different varieties of tourmaline based on their color.

Blue tourmaline does not share the same classification or characteristics as sapphire, which is a corundum mineral, or cyanite, which is a silicate mineral typically found in metamorphic rocks. Similarly, blue zircon is another distinct mineral with its own unique properties and should not be confused with blue tourmaline. Thus, the term "indicolite" is specific and recognized in the gemological world for identifying this particular variety of blue tourmaline.