NEPHRITE
Nephrite Jade: Toughness, Properties, Origins & Care
Nephrite is one of the two minerals traditionally called jade, the other being jadeite. Nephrite is an interlocking aggregate of amphibole minerals, a structure that gives it exceptional toughness. It is found in a range of colors, especially green, white, gray, and dark tones.
Table of Contents
Formation and Geological Setting
Nephrite forms in certain metamorphic environments, including altered ultramafic rocks and contact zones where fluids change the composition of host rocks. Important historical and modern sources include regions of China, New Zealand, Canada, and elsewhere.
Properties and Appearance
Nephrite is made mainly of tremolite-actinolite amphiboles and has a fibrous, interlocking texture. Its Mohs hardness is about 6–6.5, but toughness can be remarkably high. Color and translucency vary with composition and texture.
Identification and Collecting
Nephrite can resemble jadeite, serpentine, quartz, and imitations. Gemological testing can identify the material and assess dyeing or other treatments. Accurate labels should distinguish nephrite from jadeite where the difference matters.
Care and Handling
Clean nephrite with mild soap and a soft cloth. Avoid harsh chemicals and strong impacts to carved edges. Store separately from harder materials to prevent scratches and protect delicate carvings.
Frequently Asked Questions
Can appearance alone confirm identity?
No. Similar materials and treatments can look alike. Use credible documentation and appropriate gemological testing when certainty matters.
What should collectors keep?
Retain locality details, seller disclosures, treatment information, and any laboratory reports with the specimen.
Further Reading & Sources
- Mindat — mineral data and localities.
- Handbook of Mineralogy — technical descriptions.
- Gemological Institute of America — gem identification and education.
- Wikipedia: Nephrite — background and references.