Synthetic stones are created artificially in a factory or laboratory, but have the same physical, chemical and optical characteristics as their natural counterparts. These stones usually have high luster, and is difficult to tell the difference from natural stones with the naked eye.
Jade is an ornamental rock. The term jade is applied to two different metamorphic rocks that are composed of different silicate minerals: nephrite and jadeite. Nephrite and jadeite were used from prehistoric periods for hardstone carving. Jadeite has about the same hardness as quartz. Nephrite is slightly softer, but is tougher (more resistant to breakage) than jadeite.