Characteristics of Kyanite:

Chemical Name: Aluminum silicate

Formula: Al₂SiO₅

Colors: Blue, green, orange, colorless

Structure: Triclinic

Hardness: 4.5-7

Specific Gravity: 3.5-3.7

Refractive Index: 1.71-1.73

Lustre: Vitreous

Streak: Colorless

Locations: Brazil, Switzerland, USA

What is Kyanite? 

Usually blue or blue-grey, and generally mixed or zoned within a single crystal, Kyanite can also be green, orange, or colorless. Kyanite mainly occurs as elongated blades that are often bent, and less commonly as radiating, columnar aggregates. Kyanite is formed during the metamorphism of clay-rich sediments. It occurs in mica schists, gneisses, and associated hydrothermal quartz veins. Until recently it was not considered a gem mineral, but in the last decades transparent material has been found. Stones cut from it rival blue sapphire in intensity of color.