Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2
Rock Type: metamorphic

Physical Properties
Hardness: 6-6.5 (Mohs), Color: Dark green to spinach green, Luster: Vitreous to greasy, Crystal structure: Monoclinic (fibrous), Cleavage: None (highly resistant to fracturing), Specific gravity: 2.90-3.03
Formation & Geological History
Formed through the regional metamorphism of magnesium-rich limestones (dolomites) or the hydrothermal alteration of ultramafic rocks. They are frequently found in mountain ranges as boulders or in riverbeds as water-worn pebbles.
Uses & Applications
Commonly used in jewelry, ornamental carvings, statues, and historical tools due to its extreme toughness and durability.
Geological Facts
Nephrite is significantly tougher than steel. It was known as the 'Stone of Heaven' in ancient China and was used to make axe heads and weapons by prehistoric cultures around the world.
Field Identification & Locations
Identify by its 'greasy' feel when polished, its extreme toughness (it does not shatter easily), and its characteristic deep green translucency when held to a light source. Commonly found in British Columbia, New Zealand, Russia, and California.
Identified on: 5/2/2026
Mode: Standard