Rather than merely being one distinct mineral species, serpentine represents a range of silicates with slightly differing compositions, including antigorite, chrysotile and lizardite. In gemological terms, members of the serpentine group are best known as jade simulants, due to their somewhat similar visual appearance to nephrite. However, genuine nephrite can usually be separated by way of its significantly higher specific gravity and hardness.
Bowenite is an especially hard variety of translucent, green to bluish-green antigorite, which makes for a far more durable and visually-appealing ornamental material than regular serpentine. It is named after the nineteenth century American geologist George T. Bowen, who first discovered the material in Rhode Island, and has also since been found elsewhere in the northeastern United States, as well as New Zealand and China. Another variety of antigorite, williamsite, possesses an attractive apple-green hue and is often sufficiently translucent for faceting.