Cordierite

The name of this stone is indebted to the French mineralogist Philippe Courtier. It is also called iolite because of its Greek root meaning purple, or sapphire of water, whose name is banned but widely used in the market.

The color of cordierite is usually dark. Its polychrome is exceptional and can strongly influence it. The lapidary also takes this into account when the size: they direct shades of blue perpendicular to the table and produce a very small house so that the stone is not too opaque.

Cordie rite can be confused with Tanzania and sapphire. Its specific gravity and refractive index are excellent elements that allow us to differentiate them. Its main mining sites are located in Sri Lanka and in Burma, but also in Brazil, Namibia and Madagascar.

     Crystalline system: orthorhombic

     Chemical composition (Mg Fe) 2 SI5 Al4) 18 aluminum silicate and magnesium

     Color: Blue violet.

     Hardness: 7.0 - 7.5

     Specific gravity: 2.54 - 2.66

     Refractive index: 1.53 - 1.55

     Dispersion: 0.017

     Polychrome: Colorless to blue-gray, grayish yellow to purple.