Grossular
Gemstone
Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca₃Al₂(SiO₄)₃ but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron. Wikipedia
Chemical formula: Ca₃Al₂Si₃O₁₂
Hardness (Mohs hardness scale): 6.5 – 7.5
Refractive index: 1.738 – 1.745
Category: Nesosilicate
Crystal class: Hexoctahedral (m3m); H-M Symbol: (4/m 3 2/m)
Crystal system: Cubic