Gemstone Glossary

Kyanite

Kyanite is a rare polymorph (with two other minerals; andalusite and sillimanite), displaying widely varying hardness within the one stone (a unique characteristic among gem types), and is an important component of spark plugs!

Kyanite is comprised of Aluminum Silicate (Al2 SiO5) with a Refractive Index of 1.71-1.75 and Specific Gravity of 3.58.


The name Kyanite is derived from the Greek kyanos meaning "blue" as the finest specimens display colors similar to Blue Sapphire. Like Diamonds, Kyanite has perfect cleavage in one direction, a fact that gem cutters take into consideration when faceting this unusual gemstone. Kyanite is commonly cut into Baguette, Octagon, Oval and Pear shapes.

While Kyanite is most commonly blue in color it can also appear as white, gray or green. A splintery stone with perfect cleavage, its hardness is different on the parallel and perpendicular axes - a very rare trait amongst gemstones. Lengthwise Kyanite's hardness is 4-5, while Crosswise it is 6-7 on the Moh's scale.

Kyanite can be found in a wide variety of locations around the world including: Brazil, India, Kenya, Mozambique, Nepal, Russia, Serbia, Switzerland, Tibet, and in the USA in the states of North Carolina and Georgia.

Kyanite's color is often not consistent throughout the crystal and can be blotchy or in streaks. Kyanite is a difficult stone to cut, making quality of faceting an important value consideration. Overall Kyanite is an affordable gem type and its unusual characteristics make it a very striking statement of individuality for those who choose to wear this little-known yet very attractive gem.