Nephrite Jade
Nephrite (Tremolite-Actinolite series) · Semi-Precious Gemstone / Decorative Stone
Crystal System
Monoclinic; commonly occurs in massive, microcrystalline, or fibrous aggregates
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 dolomites, or the metasomatism of ultramafic rocks
About This Crystal
Deep forest green to blackish-green sphere with a vitreous to greasy luster. It is translucent to opaque with a mottled, interlocking fibrous structure that creates extreme toughness. It shows white circular banding or surface bruising and slight internal speckling.
Physical Characteristics
Color: Dark Green; Streak: White; Cleavage: None (in massive form); Fracture: Splintery to uneven; Specific Gravity: 2.90–3.03; Fluorescence: Typically inert
Optical Properties
Refractive Index: ~1.600–1.627; Birefringence: 0.027 (usually not visible in massive form); Pleochroism: Weak; Optical Phenomenon: Occasional chatoyancy in rare fibrous specimens
Hardness & Durability
Origin Region
Notable sources include British Columbia (Canada), New Zealand, China (Hetian), Russia, and Wyoming (USA)
Hardness & Durability
Mohs Hardness: 6.0–6.5; Toughness: Exceptional (highest of all gemstones due to felted structure); Stability: Very stable
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh chemicals and acids; store separately to avoid scratching softer stones; generally resistant to impact
Rarity & Value
Common to Uncommon; value is dictated by color uniformity, translucency, and lack of inclusions; prices range from affordable decorative items to high-value jewelry
Special Characteristics
Renowned for its extreme mechanical toughness; exhibits 'felted' microscopic structure; can show white 'weathering' rinds or circular impact marks (bruising) as seen in this specimen
Lore & History
Historically significant in Ancient China (the 'Stone of Heaven') and by the Māori of New Zealand (Pounamu). Traditionally associated with the heart chakra, longevity, and protection.