Kyanite

Kyanite Overview (Al2SiO5 - aluminium silicate)

Kyanite, whose name derives from the Greek word kyanos, meaning blue, is a typically blue silicate mineral, commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. Kyanite is a diagnostic mineral of the Blueschist Facies of metamorphic rocks.

Kyanite is a member of the aluminosilicate series, which also includes the polymorph andalusite and the polymorph sillimanite. Kyanite is strongly anisotropic, in that its hardness varies depending on its crystallographic direction. While this is a feature of almost all minerals, in kyanite this anisotropism can be considered an identifying characteristic.

At temperatures above 1100 °C, kyanite decomposes into mullite and vitreous silica via the following reaction: 3(Al2O3·SiO2) → 3Al2O3·2SiO2 + SiO2. This transformation results in an expansion.

Uses of Kyanite

Kyanite is used primarily in refractory and ceramic products, including porcelain plumbing fixtures and dishware. It is also used in electrical insulators and abrasives. Kyanite has been used as a gemstone, though this use is limited by its anisotropism and perfect cleavage. Kyanite is one of the index minerals that are used to estimate the temperature, depth, and pressure at which a rock undergoes metamorphism. Finally, as with most minerals, kyanite is a collector's mineral.

Kyanite: Related Minerals

Kyanite is usually found in association with its polymorphs, as well as other silicate minerals. These include:

andalusite, Al2SiO5
sillimanite, Al2SiO5
quartz, SiO2
staurolite, Fe2Al9Si4O22(OH)2
micas, AB2-3(X, Si)4O10(O,F,OH)2
garnets, A3B2(SiO4)3

Alternate Names for Kyanite

Kyanite has several alternative names, including disthene, munkrudite and cyanite. White-grey kyanite is also called rhaeticite.

Tips for How to Identify Kyanite

Kyanite's elongated, columnar crystals are usually a good first indication of the mineral, as well as its color (when the specimen is blue). Associated minerals are useful as well, especially the presence of the polymorphs or staurolite, which occur frequently with kyanite. However, the most useful characteristic in identifying kyanite is its anisotropism. If one suspects a specimen to be kyanite, verifying that it has two distinctly different hardnesses on perpendicular axes is a key to identification.

Metaphysical Properties of Kyanite

Kyanite is a powerful healing gemstone with the energy of the blue light spectrum. The most beautiful Kyanite gemstones have a Kashmir Sapphire color. Kyanite is an excellent stone for meditation and is known by healers to balance the subtle body effortlessly. It dispels blockages, helping to evenly clear the pathways of the body’s energy meridians.

Buying Kyanite

Arkadian Collection offers a wide selection of kyanite, kyanite pendants and other handmade kyanite jewelry.

Part of the information on this page was adapted from Wikipedia. The rest is original content by Arkadian Collection.