Olivine is a magnesium iron silicate mineral and belongs to the orthorhombic crystal system. The crystals are short columnar. Complete crystals are rare. Most of them are irregular round granular aggregates. They have glass luster, 透明から半透明, と硬さ 6.5-7.0. Olivine is a kind of self-colored gemstone, which is green due to iron [...]
