Nephrite Jade
Tremolite-Actinolite variety Nephrite · Semi-Precious Gemstone / Ornamental Stone
Crystal System
Monoclinic; occurs in a massive microcrystalline or felted fibrous habit where individual crystals are too small to be seen.
Mineral Group
Silicates (Inosilicates; Amphibole Group)
Chemical Formula
Ca2(Mg,Fe)5Si8O22(OH)2
Formation Process
Metamorphic; specifically through the contact metamorphism of magnesium-rich limestones or the metasomatic alteration of basic igneous rocks.
About This Crystal
These beads exhibit a gradient from mutton-fat white to spinach green. They show a characteristic waxy to vitreous luster, varying from translucent to nearly opaque. The texture appears smooth with a slight oily depth characteristic of nephrite.
Physical Characteristics
Color: White, pale green, olive, to dark green. Streak: White. Cleavage: None visible in massive form. Specific Gravity: 2.90–3.03. Fracture: Splintery to uneven. Resilience is exceptionally high due to the interlocking fibrous structure.
Optical Properties
Refractive Index: ~1.606–1.632. Birefringence: None observable in massive samples. Usually doubly refractive but aggregate-like. Shows no pleochroism in this form.
Hardness & Durability
Origin Region
Hetian (Xinjiang, China), British Columbia (Canada), New Zealand, Russia, and Wyoming (USA). Found in metamorphic environments.
Hardness & Durability
Mohs Hardness: 6.0–6.5. Exceptional toughness (highest of any natural stone) due to felted fibrous structure, making it extremely resistant to breaking or chipping.
Care & Maintenance
Safe to clean with warm soapy water and a soft cloth. Avoid ultrasonic cleaners and harsh chemicals. Store separately to prevent scratching by harder stones like quartz or sapphire.
Rarity & Value
Moderately common globally, though high-quality 'Mutton Fat' white jade and vibrant greens are highly valuable. Value depends on color uniformity, translucency, and texture.
Special Characteristics
Known for its 'greasy' feel when polished and its extreme mechanical strength. Does not usually show fluorescence but may exhibit a faint green glow under longwave UV if certain trace elements are present.
Lore & History
Historically revered in China for over 5,000 years as the 'Imperial Gem.' Symbolizes purity, longevity, and moral integrity. In Maori culture (New Zealand), it is known as Pounamu and used for sacred 'hei-tiki' carvings.