Serpentine is a group of common rock-forming hydrous magnesium iron phyllosilicate ((Mg, Fe)3Si2O5(OH)4) minerals; it is also often rich in other metal ores, including chromium, manganese, cobalt and nickel.
Most serpentines are opaque to translucent, light (specific gravity between 2.22.9), soft (hardness 2.54), infusible and susceptible to acids. All are microcrystalline and massive in habit, never being found as single crystals. Lustre may be vitreous, greasy or silky. Colours range from white to grey, yellow to green, and brown to black, and are often splotchy or veined. Many are intergrown with other minerals, such as calcite and dolomite. Occurrence is worldwide; New Caledonia, Canada (Quebec), USA (northern California), Afghanistan, Cornwall, China, France, Norway and Italy are notable localities
Serpentine can be an attractive green stone that takes a nice polish and is suitable for carving. It has been used as a substitute for jade and is sometimes difficult to distinguish from jade, a testament to the beauty of finer serpentine material. Serpentine rocks are classified as common serpentine and precious serpentine, the common serpentine being darker, less translucent, and sometimes impure.