Serpentinite

Serpentinite is common beneath the oceanic crust, where it forms by the alteration of the mantle rock peridotite. (See more about serpentinization and its importance in plate tectonics.) But it is seldom seen on land except in rocks from subduction zones, where oceanic rocks may be preserved.

Most people call it serpentine (SER-penteen) or serpentine rock, but serpentine is the set of minerals that make up serpentinite (ser-PENT-inite). It gets its name from its resemblance to snakeskin, with a mottled color, waxy or resinous luster and curving, polished surfaces. Serpentinite is a sexy rock.

Serpentinite is low in plant nutrients and high in toxic metals. Thus the vegetation on the so-called serpentine landscape is dramatically different from other plant communities, and serpentine barrens contain many specialized, endemic species.

Serpentinite can contain chrysotile, the serpentine mineral that crystallizes in long, thin fibers. This is the mineral commonly known as asbestos.

A big close-up picture of serpentinite is available as a free wallpaper image.

For more photos see the Serpentinite Gallery or the Metamorphic Rocks Gallery.

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