Any of a group of magnesium-rich silicate minerals whose composition resembles Mg 3 Si 2 O 5 (OH) 4 .
Serpentine generally occurs in three forms: as chrysotile , the most common variety of asbestos ; and as antigorite or lizardite, both of which are commonly massive and fine-grained. Named in allusion to its resemblance to a snake's skin, serpentine is usually grayish, white, or green but may be yellow or green-blue. It takes a high polish and is sometimes used as an ornamental stone.