metamorphic
Nephrite Jade / Pounamu
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Hardness: 6-6.5 Mohs; Color: Deep green to sage green (iron inclusions); Luster: Greasy to waxy; Texture: Ultra-fine interlocking fibrous structure (actinolite-tremolite); Cleavage: None/tough; Specific Gravity: 2.9–3.03.
- Hardness
- 6-6
- Color
- Deep green to sage green (iron inclusions)
- Luster
- Greasy to waxy
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: Deep green to sage green (iron inclusions); Luster: Greasy to waxy; Texture: Ultra-fine interlocking fibrous structure (actinolite-tremolite); Cleavage: None/tough; Specific Gravity: 2.9–3.03.
Formation & geological history
Formed through low-grade metamorphism of ultramafic rocks in subduction zones. Typically found as water-worn pebbles in riverbeds or beaches where they have been eroded from parent rock and smoothed by water action over thousands of years.
Uses & applications
Used extensively for high-end jewelry, traditional carvings (Maori hei-tiki), ornamental sculpture, and tool-making due to its extreme toughness and resistance to fracturing.
Geological facts
Nephrite is actually tougher than diamond because of its felt-like interlocking crystal structure, making it incredibly difficult to break even with a hammer. In New Zealand, it is known as Pounamu and is considered a national treasure with deep cultural significance.
Field identification & locations
Identify in the field by its 'greasy' feel when wet, high density compared to surrounding rocks, and translucent edges when held to a light source. Commonly found on the West Coast of New Zealand, British Columbia, and parts of Wyoming.
More like this
