Jade
Nephrite · Semi-Precious Gemstone / Decorative Stone
Crystal System
Monoclinic system, occurring typically in massive, fibrous, or felted aggregates.
Mineral Group
Silicates, specifically the amphibole group.
Chemical Formula
Ca2(Mg,Fe)5Si8O22(OH)2
Formation Process
Metamorphic formation, usually through metasomatism involving the alteration of serpentinites or dolomitic limestones under moderate to high pressure and low to moderate temperatures.
About This Crystal
The specimen is a smooth, oval-shaped cabochon set in a decorative silver ring. It exhibits an olive-green to medium green color with subtle mottled internal variations and a translucent to opaque appearance. The luster is characteristically greasy to vitreous when polished.
Physical Characteristics
Body color is olive to dark green, with a white streak. Cleavage is distinct in two directions at intersecting angles of around 56 and 124 degrees, though rarely seen in massive cabochons. Fracture is splintery to uneven due to its interlocking fibrous structure. Specific gravity ranges from 2.90 to 3.03. It is renowned for its exceptional toughness rather than absolute hardness, making it practically unbreakable under normal wear.
Optical Properties
Biaxial negative with refractive indices typically around 1.606 to 1.632. Birefringence is weak, around 0.021 to 0.027. It is doubly refractive and displays no significant pleochroism or special optical phenomena in this variety.
Hardness & Durability
Origin Region
Notable sources include British Columbia (Canada), China, Russia, and the United States (Wyoming). It typically forms in metamorphic environments.
Hardness & Durability
Mohs hardness is 6.0 to 6.5. Despite being slightly softer than quartz, nephrite has legendary toughness due to its interlocking micro-fibrous crystal structure, making it exceptionally durable and resistant to chipping or breaking, perfectly suitable for daily jewelry wear.
Care & Maintenance
Care is straightforward. Clean with warm soapy water and a soft brush. Avoid harsh chemical cleaners, prolonged exposure to extreme heat, and ultrasonic cleaners if internal fractures are suspected. Store separately from harder gemstones like diamonds or corundum to prevent surface scratching.
Rarity & Value
Common to Uncommon depending on the grade, color, and translucency. Value is determined by purity of color (intense spinach green is prized), translucency, and absence of dark inclusions. Prices range from affordable commercial grades to high-end collector specimens.
Special Characteristics
The defining characteristic of nephrite is its interlocking fibrous micro-structure, which grants it an extraordinary level of toughness that surpasses that of diamond in terms of resistance to fracture.
Lore & History
Nephrite jade has a rich history spanning thousands of years, particularly in ancient Chinese culture where it was considered the stone of heaven, symbolizing purity, moral integrity, and status. In crystal healing traditions, it is associated with the heart chakra, representing abundance, emotional balance, and harmony, though these are cultural beliefs rather than scientifically verified claims.