Nephrite Jade
Nephrite (Actinolite-Tremolite series) · Semi-Precious Gemstone
Crystal System
Monoclinic; typically occurs in massive, microcrystalline fibrous compact aggregates
Mineral Group
Silicates (Inosilicates), specifically the Amphibole group
Chemical Formula
Ca2(Mg,Fe)5Si8O22(OH)2
Formation Process
Metamorphic; typically forms through the contact metamorphism of magnesium-rich limestones (dolomites) or through the hydrothermal alteration of ultramafic rocks
About This Crystal
The beads exhibit a translucent to near-opaque pale sage or greenish-grey color with a characteristic greasy to waxy luster. They show a smooth, fine-grained texture consistent with the interlocking fibrous structure of nephrite.
Physical Characteristics
Color: Sage green to grey-green; Streak: White; Cleavage: Prismatic (though not visible in massive form); Fracture: Splintery to conchoidal; Specific Gravity: 2.90–3.03; Fluorescence: Usually inert
Optical Properties
Refractive Index: 1.606–1.632; Birefringence: 0.027 (usually not measurable in aggregates); Pleochroism: Weak; Optical Phenomenon: Greasy luster due to fibrous structure
Hardness & Durability
Origin Region
Notable sources include British Columbia (Canada), Xinjiang (China), New Zealand, Russia, and Australia
Hardness & Durability
Mohs Hardness: 6–6.5; Toughness: Exceptional (highest of any natural stone due to its interlocking fibrous structure); very stable and highly wearable
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh chemicals and ultrasonic cleaners if the stone has surface-reaching fractures; store away from harder gems like sapphire or diamond
Rarity & Value
Moderately common; value is determined by color uniformity, translucency, and lack of dark inclusions; Hetian jade (Xinjiang) is the most valued variety
Special Characteristics
Renowned for its extreme toughness—it is more difficult to break than steel by impact; often displays chatoyant properties in rare 'Cat's Eye' nephrite specimens
Lore & History
Historically known as the 'Stone of Heaven' in China, used for over 5,000 years for ritual objects and weaponry. Traditionally associated with longevity, protection, and the heart chakra in healing practices.