metamorphic
Nephrite Jade
Ca2(Mg, Fe)5Si8O22(OH)2 (Tremolite-Actinolite series)
Hardness: 6-6.5 Mohs; Color: Mottled green, grey-green, to olive; Luster: Waxy to greasy; Crystal Structure: Monoclinic (interlocking fibrous microstructures); Cleavage: None (highly resistant to fracturing); Specific Gravity: 2.90–3.03
- Hardness
- 6-6
- Color
- Mottled green, grey-green, to olive
- Luster
- Waxy to greasy
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-6.5 Mohs; Color: Mottled green, grey-green, to olive; Luster: Waxy to greasy; Crystal Structure: Monoclinic (interlocking fibrous microstructures); Cleavage: None (highly resistant to fracturing); Specific Gravity: 2.90–3.03
Formation & geological history
Formed through regional metamorphism of magnesium-rich limestones (dolomites) or ultramafic igneous rocks in the presence of water-rich fluids. Often found in serpentinite belts.
Uses & applications
Extensively used in jewelry (cabochons, beads), decorative carvings, sculpture, and historically for tool-making (ax heads) due to its extreme toughness.
Geological facts
Nephrite is actually tougher than Diamond, not in hardness, but in 'tenacity,' meaning it is harder to break or shatter because of its matted, interlocking fibrous structure. It has been used by humans for over 5,000 years.
Field identification & locations
Identify by its 'soapy' or waxy feel when polished and its heavy weight for its size. In the field, look for smooth, water-worn boulders in riverbeds in regions like British Columbia, New Zealand, or Wyoming. It won't scratch with a steel knife but may be scratched by quartz.
More like this
