Tourmaline is a six-member ring cyclosilicate having a trigonal crystal system. It occurs as long, slender to thick prismatic and columnar crystals that are usually triangular in cross-section, often with curved striated faces. ... All hemimorphic crystals are piezoelectric, and are often pyroelectric as well.

Is tourmaline an expensive gem?

Prices. The prices of tourmaline vary tremendously, depending on the variety and quality. Most expensive are the Paraíba tourmalines, which may reach tens of thousands of dollars per carat. Chrome tourmalines, rubellites and fine indicolites and bi-colors may sell for as much as $1000/ct. or more.

How much is a tourmaline crystal?

The price of Tourmaline per carat largely depends upon the quality and origin of the gemstone. Note - Generally, Tourmaline price in India starts from ₹150 per carat ($3 approx.) and goes up to ₹ 3,000 per carat ($45 approx.)