This is an NG spinel stone in deep black with a round cut. It is well cut and polished for maximum luster. It is excellent for making different kinds of jewelry like necklaces, earrings, bracelets, and so on.

• Hardness: 7-7.5.
• Refractive index: 1.61-1.64.
• Density: 3.0-3.3g/cm³.
• Wax casting: suitable 100% .
• Melting temperature: 1,600-1,750℃.