1 Spinels are minerals composed of magnesium-aluminum oxides. Because they contain magnesium, iron, zinc, manganese and other elements, they can be divided into many kinds, such as aluminum spinel, iron spinel, zinc spinel, manganese spinel and chromium spinel. Because of different elements, different spinel can have different colors. For example, magnesium spinel is between red, blue, green, brown or colorless. Zinc spinel is dark green. Spinel is black and so on. Spinel is a hard glassy octahedron or particles and blocks. They occur in igneous rocks, granite pegmatite and metamorphic limestone. Some transparent and beautiful spinels can be used as gems, while others can be used as magnetic materials containing iron. More than 200 kinds of spinel have been produced by artificial methods.
2. moissanite, named after Dr. Henry Mosan. Also known as Mosan stone and moissanite, the chemical name is synthetic silicon carbide, which is similar to diamond in appearance and is often used as a substitute for diamond. It is also a kind of gem whose physical characteristics are closest to natural diamonds. Mosang Diamond was originally developed by overseas companies in Europe and America, with an investment of 45 million US dollars. It was launched as a patented product in June, 1998. Its patent protection expires on 20 16, and all countries in the world are producing Mosan diamond. Its chemical composition is SiC, almost colorless, with refractive index of 2.56-2.69, dispersion of 0. 104, birefringence of 0.043, hardness of 9.25 and density of 3.22g/cm3.