Grandidierite 1.59gr

Grandidierite

Grandidierite is a very rare mineral that was first discovered in southern Madagascar in the early 20th century. As Grandidierite is quite hard, the high quality material has been cut as gems, making it one of the rarest gems.

Gemologically, grandidierite is a magnesium aluminum borosilicate. It has a hardness of 7 to 7.5 on the Mohs scale, similar to garnet, and a refractive index of 1.590-1.623.

It forms in the orthorhombic crystal system. Grandidierite is typically bluish-green in color and derives its distinctive color from traces of iron. The gemological material is translucent to transparent. Completely transparent samples are absolutely rare.