1. Accessoire de cotillon.
2. Tube en spirale.
Group of minerals, hydrous magnesium silicate, Mg3Si2O5(OH)4, occurring in soft metamorphic rocks and usually dark green. The fibrous form chrysotile is a source of asbestos; other forms are antigorite and lizardite Serpentine minerals are formed by hydration of ultrabasic rocks during metamorphism. Rare snake-patterned forms are used in ornamental carving.