We are offering jade gemstone. Chemical composition sodium aluminum silicate. color a wide range of colors including white, green, yellow, red, orange, violet, and black. refractive index r.i. 1.64-1.67 durability hardness 6.5-7. Very tough. crystal structure monoclinic specific gravity 3.25-3.36. sources occurrences major sources include burma, new zealand, guatemala, and siberia. Prized for carvings, frequently from china