metamorphic
Serpentinite
Serpentinite (complex of Antigorite, Lizardite, and Chrysotile, Mg3Si2O5(OH)4)
Hardness: 3–6 on Mohs scale; Color: typically green (light to dark), greenish-gray, or black; Luster: waxy, greasy, or silky; Crystal Structure: Monoclinic; Cleavage: poor/irregular; Specific Gravity: 2.5–2.8.
- Hardness
- 3–6 on Mohs scale
- Color
- typically green (light to dark), greenish-gray, or black
- Luster
- waxy, greasy, 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: typically green (light to dark), greenish-gray, or black; Luster: waxy, greasy, or silky; Crystal Structure: Monoclinic; Cleavage: poor/irregular; Specific Gravity: 2.5–2.8.
Formation & geological history
Formed through serpentinization, a low-temperature metamorphic process where ultramafic rocks (like peridotite) from the Earth's mantle react with water. Common in ophiolite complexes and subduction zones.
Uses & applications
Used as decorative architectural stone (countertops and facades), a source of magnesium, and historically as a source of asbestos. High-quality translucent varieties are used in carvings and jewelry.
Geological facts
Serpentinite is the state rock of California. It often creates 'serpentine barrens,' unique ecosystems where the soil is toxic to many plants but supports rare, endemic species that have adapted to high metal levels.
Field identification & locations
Identify in the field by its distinctive green color, 'greasy' or slippery texture, and presence of slickensides (polished, grooved surfaces). It is often found in mountainous regions near tectonic plate boundaries.
More like this
