Nephrite Jade
Nephrite (Tremolite-Actinolite series) · Semi-Precious Gemstone / Decorative Stone
Crystal System
Monoclinic; typically occurs in massive, microcrystalline, or fibrous compact aggregates rather than distinct crystals.
Mineral Group
Silicates (Inosilicates, Amphibole group)
Chemical Formula
Ca2(Mg,Fe)5Si8O22(OH)2
Formation Process
Metamorphic; typically forms through the contact metamorphism of magnesium-rich limestones or the hydrothermal alteration of ultramafic rocks.
About This Crystal
A dense, tough, opaque to translucent stone with a greasy to vitreous luster. This specimen is a dark forest green with subtle mottled patterns and a polished spherical shape.
Physical Characteristics
Color: Dark green; Streak: White; Cleavage: Prismatic (rarely visible in massive form); Fracture: Splintery to granular; Specific Gravity: 2.90–3.03; Fluorescence: Usually inert.
Optical Properties
Refractive Index: 1.600–1.627; Birefringence: 0.027 (often masked in massive aggregates); Polycrystalline aggregate structure results in a dull to greasy luster.
Hardness & Durability
Origin Region
Notable sources include British Columbia (Canada), New Zealand, China (Hetian), Russia, and Australia. Usually found in metamorphic settings.
Hardness & Durability
Mohs Hardness: 6.0–6.5; Exceptional toughness due to its interlocking fibrous structure, making it highly resistant to fracturing or chipping.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh chemicals and ultrasonic cleaners. Store away from harder stones like diamonds or sapphires to prevent scratching.
Rarity & Value
Relatively common; value is determined by color uniformity, translucency, and the absence of black chromite inclusions. Prices range from affordable decor to expensive jewelry grades.
Special Characteristics
Renowned for its extreme mechanical toughness; sometimes exhibits a slightly 'mottled' or 'cloudy' internal structure when backlit (translucency).
Lore & History
Historically used for weapons and tools due to its toughness; highly revered in Chinese culture as the 'Stone of Heaven' symbolizing virtue, purity, and longevity.