Black Nephrite Jade
Nephrite var. Actinolite/Tremolite · Semi-Precious Gemstone / Ornamental Stone
Crystal System
Monoclinic; typically occurs in massive, microcrystalline, or fibrous aggregates (interlocking felt-like structure)
Mineral Group
Silicates (Inosilicates) - Amphibole Group
Chemical Formula
Ca2(Mg,Fe)5Si8O22(OH)2
Formation Process
Metamorphic: formed through the metasomatism of ultramafic rocks or at the contact of dolomite and silicic rocks under high pressure.
About This Crystal
A dense, opaque stone with a deep charcoal to jet-black color. The surface shows a waxy to greasy luster with white-to-greyish scratches and pitting typical of rough, river-worn material. It features a compact, tough texture with some visible white speckling or mineral inclusions.
Physical Characteristics
Color: Black; Streak: White; Cleavage: Not visible due to massive form; Fracture: Splintery to uneven; Specific Gravity: 2.90–3.03; Fluorescence: Typically inert.
Optical Properties
Refractive Index: 1.606–1.632; Opaque to translucent on thin edges; lacks pleochroism in massive form; single refractive aggregate.
Hardness & Durability
Origin Region
Prominent sources include British Columbia (Canada), Xinjiang (China), New Zealand, and Wyoming (USA). Found in metamorphic contact zones.
Hardness & Durability
Mohs Hardness: 6.0–6.5; Exceptional toughness due to its interlocking fibrous structure, making it one of the most fracture-resistant stones.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh chemicals and ultrasonic cleaners. Store separately from harder stones like diamonds or sapphires to prevent scratches.
Rarity & Value
Relatively common but higher-quality 'jet black' specimens are more valuable. Price varies by size, polish, and origin. Usually untreated, though occasionally waxed.
Special Characteristics
Renowned for its extreme toughness; often used for carving because it does not chip easily. High iron content contributes to the deep black coloration.
Lore & History
Historically used for weapons, tools (celts), and ritual ornaments. In many cultures, black jade is considered a stone of protection and grounding, used in traditional Chinese art for centuries as a symbol of longevity and status.