Dimension: 54mm x 50mm x 25mm
Grandidierite is an extremely rare mineral and gem that was first discovered in 1902 in southern Madagascar.
Optical properties: Biaxial (-)
Crystal system: Orthorhombic
Color: Bluish green
Hardness: 7 to 7.5
Refractive Index: 1.590 to 1.623
Grandidierite have been found in only a few locations around the world, including Malawi, Namibia and Sri Lanka and few gem quality specimens have come mainly from Madagascar.