metamorphic
Serpentinite
Serpentinite (composed primarily of minerals in the serpentine group: (Mg,Fe)3Si2O5(OH)4)
Hardness: 3-6 on Mohs scale; Color: Greenish, greyish-green, to dusky green; Luster: Greasy, waxy, or silky; Crystal structure: Monoclinic; Cleavage: Often poor but can exhibit fiber-like structures; Specific Gravity: 2.2 to 2.9
- Hardness
- 3-6 on Mohs scale
- Color
- Greenish, greyish-green, to dusky green
- Luster
- Greasy, waxy, or silky
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-6 on Mohs scale; Color: Greenish, greyish-green, to dusky green; Luster: Greasy, waxy, or silky; Crystal structure: Monoclinic; Cleavage: Often poor but can exhibit fiber-like structures; Specific Gravity: 2.2 to 2.9
Formation & geological history
Formed through the hydrothermal metamorphism of ultramafic rocks (like peridotite) from the Earth's mantle, usually during subduction and mountain-building events. This process is known as serpentinization.
Uses & applications
Used as an architectural stone (Verde Antique), decorative sculpture material, source of magnesium, and historically as a source of asbestos.
Geological facts
Serpentinite is the official State Rock of California. Its unique chemistry creates 'serpentine barrens' which are ecosystems where only specifically adapted rare plants can grow due to high magnesium and low calcium levels.
Field identification & locations
Identify by its waxy-to-greasy feel and characteristic green mottled appearance. It is commonly found in ophiolite complexes and along tectonic plate boundaries. In the field, look for 'slickensides' or polished, grooved surfaces.
More like this
