metamorphic
Serpentinite
Serpentinite (composed primarily of serpentine group minerals like lizardite, antigorite, and chrysotile)
Hardness: 2.5–6 on Mohs scale; Color: typically green/dark green with yellowish or black streaks; Luster: waxy, greasy, or silky; Crystal Structure: Monoclinic; Cleavage: poor; Specific Gravity: 2.5–2.6.
- Hardness
- 2
- Color
- typically green/dark green with yellowish or black streaks
- 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: 2.5–6 on Mohs scale; Color: typically green/dark green with yellowish or black streaks; Luster: waxy, greasy, or silky; Crystal Structure: Monoclinic; Cleavage: poor; Specific Gravity: 2.5–2.6.
Formation & geological history
Formed through the hydration and metamorphic transformation of ultramafic rocks (like peridotite) from the Earth's mantle, a process called serpentinization. This often occurs at tectonic plate boundaries/subduction zones.
Uses & applications
Used as a source of asbestos (chrysotile), decorative stone (for countertops and sculptures), and historically as an industrial magnesium source.
Geological facts
Serpentinite is the official state rock of California. It often creates 'serpentine barrens,' which are unique ecosystems where low-nutrient soil prevents many plant species from growing, leading to high levels of endemic flora.
Field identification & locations
Identify by its 'serpentine' or scaly snake-skin texture and waxy feel. It is commonly found in ophiolite complexes along former or current tectonic collision zones. Collectors should look for the characteristic mottled green color.
More like this
