Kyanite

Mineral formula: Al₂(SiO₄)O

Crystal system: triclinic

Crystal habit: bladed or tabular, often in sprays

Cleavage: Perfect on (100), good on (010)

Fracture: Splintery

Color: blue, white, light gray, green, black

Luster: vitreous, sub-vitreous, greasy, pearly

Diaphaneity: transparent to translucent

Moh’s scale hardness: 5 ½ - 7

Streak: colorless

Specific gravity: 3.53 – 3.67

Named after: the Greek word "kyanos", meaning "blue," the common color of the species, in 1789 by Abraham Gottlieb Werner.

Type locality: the kyanite studied by Werner included specimens from Austria and other locations.

Geological occurrence: a common silicate mineral in moderately high-pressure regional metamorphic rocks.

Energetic properties: Melody, in her book Love Is In The Earth, says “This is one of the few minerals in the mineral kingdom which never needs cleansing or clearing.  It will not accumulate or retain negative energy or vibrations. The energy of Kyanite is unlimited in application, making it one of the very best attunement stones....It brings tranquility and a calming effect to the whole being…Kyanite Facilitates Meditation!...”

Kyanite is a common metamorphic silicate mineral and is one of the index minerals that are used to estimate the temperature, depth, and pressure at which a rock undergoes metamorphism.  It is a polymorph of andalusite and sillimanite – same chemistry, different crystal structures. At a specific pressure (0.4GPa) temperature (500ºC) range - the triple point - it is possible for all three mineral phases to co-exist..

Kyanite occurs in gneiss, schist, pegmatite, and quartz veins resulting from high pressure regional metamorphism of principally pelitic rocks.  It occurs associated with staurolite, andalusite, sillimanite, talc, hornblende, gedrite, mullite and corundum.  

Kyanite is used primarily in refractory and ceramic products.  It is also used in electronics, electrical insulators and abrasives.  Kyanite has been used as a semiprecious gemstone.