metamorphic
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Hardness: 6.0–6.5 Mohs. Color: Deep spinach green, grey-green, or blackish-green. Luster: Greasy to vitreous. Crystal structure: Monoclinic (fibrous interlaced structure). Cleavage: None (extremely tough fracture). Specific gravity: 2.90–3.03.
- Hardness
- 6
- Color
- Deep spinach green, grey-green, or blackish-green
- Luster
- Greasy to vitreous
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.0–6.5 Mohs. Color: Deep spinach green, grey-green, or blackish-green. Luster: Greasy to vitreous. Crystal structure: Monoclinic (fibrous interlaced structure). Cleavage: None (extremely tough fracture). Specific gravity: 2.90–3.03.
Formation & geological history
Formed via contact metamorphism or metasomatism of magnesium-rich rocks (like dolomite) or ultramafic rocks (like serpentinite). The interlocking fibrous structure makes it the toughest natural stone known. Most deposits are associated with subduction zones.
Uses & applications
Extensively used in jewelry (beads, cabochons), ornamental carvings, sculpture, and historically for tool making (axes, knife blades) due to its extreme toughness.
Geological facts
Nephrite was known as the 'Axe-stone' because its toughness prevented the blades from shattering upon impact. It served as the primary source of 'Jade' in China for thousands of years before Jadeite was introduced from Myanmar in the 18th century.
Field identification & locations
Identify by its waxy/greasy luster and very high toughness; it is difficult to break with a hammer. Common locations include British Columbia (Canada), New Zealand, Wyoming (USA), and Russia. Look for smooth, water-worn cobbles in riverbeds near serpentine belts.
More like this
