Nephrite Jade
Nephrite (Variety of Tremolite-Actinolite Series) · Semi-Precious Gemstone and Decorative Stone.
Crystal System
Monoclinic; typically occurs in compact, microcrystalline, felted fibrous masses (massive or nephritic habit).
Mineral Group
Silicates; specifically Inosilicates (Amphibole group).
Chemical Formula
Ca2(Mg,Fe)5Si8O22(OH)2
Formation Process
Metamorphic, specifically through hydrothermal metasomatism (contact metamorphism or regional metamorphism) where hot aqueous fluids interact with serpentinites or dolomitic limestones under moderate to high temperatures and pressures.
About This Crystal
The specimen consists of tumbled, polished green stones with drilled holes, typical of carved beads or pendants. The color ranges from olive green to a deep, dark forest green with subtle color zoning and natural cloud-like internal variations. They exhibit a sub-vitreous to greasy luster, ranging from translucent to opaque, with smooth, tumbled surface textures.
Physical Characteristics
Color includes various shades of green, dark green, and greyish-green; streak is white; cleavage is prismatic (though rarely seen in massive nephrite due to interlocking fibers); fracture is splintery to uneven; specific gravity is approximately 2.95 to 3.10; tenacity is exceptionally tough and resilient due to the microcrystalline interlocking fibrous structure; non-magnetic; inert under UV light.
Optical Properties
Refractive index ranges from 1.606 to 1.632; biaxial negative; birefringence is weak (around 0.017 to 0.027); pleochroism is usually weak to moderate in green shades.
Hardness & Durability
Origin Region
Notable sources include British Columbia (Canada), Xinjiang (China), Siberia (Russia), Wyoming (USA), and New Zealand. Forms in metamorphic and metasomatic environments.
Hardness & Durability
Mohs hardness is 6 to 6.5, making it very durable and highly resistant to breaking due to its interlocking fibrous structure, which gives it superior toughness compared to jadeite.
Care & Maintenance
Easy to care for; clean with warm soapy water and a soft brush; avoid harsh chemicals and prolonged exposure to extreme heat. Ultrasonic and steam cleaners should be used with caution.
Rarity & Value
Common to Uncommon depending on the grade, color, and origin. High-transparency or intensely colored mutton-fat or deep spinach green nephrite from historic sources commands higher prices, while standard tumbled specimens are relatively affordable.
Special Characteristics
Renowned for its extreme toughness rather than hardness, due to the micro-fibrous interlaced texture that makes it virtually unbreakable by ordinary blows. Often features natural inclusions of other minerals like magnetite or chromite.
Lore & History
Historically revered in ancient Chinese civilizations, Mesoamerican cultures (Maori of New Zealand, Olmecs, and Mayans) for weapons, tools, carvings, and ceremonial ornaments. Symbolizes purity, serenity, wisdom, and protection. Associated traditionally with the Heart Chakra in modern crystal healing.