A gemstone containing a great variety of colors: a deep violet blue, a clear light blue and a honey brown, depending on the angle at which it is seen.
Formula: Mg2Al4SiO18
Hardness: 7 -7.5
Density: 1.527 – 1.578 g/cm3
Refractive Index: 1.544 – 1.553 DR: 0.008 – 0.018
Color: blue, violet, brown, colorless
Countries of Origin:
India, Sri Lanka, Tanzania, Brazil
Birthstone: November