Kyanite (Kyanite): Properties, Colors, Uses and Complete Information
In gemology, disthene is known for its blue variety called cyanite or kyanite but there are actually other colors that are much rarer and highly sought after by collectors.
Etymology
The name "kyanite" comes from the Greek "dis" (two) and "sthenos" (strength), referring to its variable hardness along the axis. Indeed, on the Mohs scale, the hardness of kyanite varies from 4.5 to 5 along the growth axis, and from 6.5 to 7 perpendicular to this axis. This makes it unique and difficult to work with.
The name "Cyanite" for the blue variety comes from the Greek "kyanos" (blue), referring to its color.
Origin and Training
Kyanite is a mineral of the silicate family, composed of aluminum silicate (Al2SiO5). It forms mainly under conditions of high pressure and low temperature in metamorphic rocks such as gneiss and schist. It is a polymorph (same chemical composition but different crystallization) of two other gemstones: andalusite and sillimanite which crystallize at different temperatures and pressures.
The main deposits of gem kyanites are found in Nepal, India, Brazil, Tanzania, etc.
Colors and Appearance
Kyanite is most often blue. Its color is due to the presence of iron ions. There is also a chrome blue variety that exhibits a lighter blue ranging from sky blue (Tanzania) to a very pretty blue-green (India and Madagascar).
Other colors of disthene that can be found are green (Brazil and Tanzania), the orange (Tanzania), white and colorless.
Kyanites are rarely pure and in the majority of cases present twin planes and/or internal breaks and rectilinear color zonations.
Perfectly clean kyanites look very similar to deep blue sapphires.
Uses
Despite its variable hardness, kyanite is sometimes cut into cabochons or facets for use as a gemstone. However, handling it requires special expertise due to its hardness, which varies depending on the axis. It is also commonly used in pendants or earrings to protect it from the impact a ring may experience.
Kyanite specimens are prized by mineral collectors for their color and interesting crystal structure.
Treatment
It is not generally subjected to treatments to improve its color or clarity.
Sold out
