Nephrite Identification Guide
How to identify nephrite jade by its extreme toughness, greasy luster, splintery fracture, and tests separating it from jadeite and serpentine.
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What Nephrite Looks Like
Nephrite is one of the two true jades, composed of microscopically interlocking tremolite-actinolite amphibole fibers. That felted fibrous structure makes it extraordinarily tough (resistant to breaking), even though it is not especially hard.
- Color: green (spinach, olive, apple), creamy white ("mutton fat"), grey, yellow, black
- Luster: greasy to waxy, oily on polished surfaces
- Transparency: translucent to opaque
- Habit: massive, compact aggregate; no visible crystals; smooth river boulders with a polished rind
- Texture: even, sometimes with subtle cloudy mottling
Step-by-Step Field ID Checklist
- Note the greasy/oily luster and waxy feel.
- Test toughness, not just hardness — nephrite resists chipping; broken edges are splintery/hackly, not cleanly conchoidal.
- Check hardness: it scratches glass (6-6.5) but a quartz/topaz point will scratch it.
- Heft it — nephrite feels moderately dense and cool.
- Tap two pieces together — true jade gives a clear, resonant ring.
Key Diagnostic Tests
- Mohs hardness: 6-6.5 (slightly softer than jadeite).
- Streak: white.
- Cleavage/fracture: no usable cleavage in the aggregate; splintery to hackly fracture (the felted fiber texture).
- Density: SG ~2.9-3.0 (lower than jadeite's ~3.3).
- Acid: no reaction (it is a silicate, not carbonate).
- Toughness: exceptional — a defining property.
Common Look-Alikes and How to Tell Them Apart
- Jadeite (the other jade): harder (6.5-7), denser (SG ~3.3), and shows a granular "dimpled orange-peel" polish texture; nephrite is fibrous with a smoother greasy surface and lower density.
- Serpentine ("new jade"/bowenite): softer (Mohs 2.5-5.5) — a knife scratches it where nephrite resists.
- Green quartz/aventurine: harder (7) but lacks nephrite's greasy luster and shows quartz's conchoidal fracture and granular sparkle.
- Green glass: bubbles, mold marks, conchoidal fracture, and lacks the fibrous toughness.
- Dyed/treated stones: dye concentrates in cracks; nephrite's color is even and natural.
Where It Is Found
Nephrite occurs in metamorphosed ultramafic and contact zones worldwide: British Columbia (Canada), Siberia (Russia), New Zealand (pounamu), China (Hetian/Khotan), Wyoming and California (USA), and Australia.
Frequently asked questions
How can you tell if nephrite jade is real?
Real nephrite has a greasy luster, a hardness of 6-6.5 (scratches glass), a splintery rather than conchoidal fracture, a density around 2.9-3.0, no acid reaction, and exceptional toughness that resists chipping. Tapping pieces gives a clear ring.
What is the difference between nephrite and jadeite?
Both are true jade, but jadeite is harder (6.5-7) and denser (SG ~3.3) with a granular orange-peel polish, while nephrite is a tougher fibrous amphibole that is softer (6-6.5), lighter (~2.9-3.0), and has a greasier, smoother surface.
How do you tell nephrite from serpentine?
Serpentine ('new jade') is much softer at Mohs 2.5-5.5 and can be scratched with a steel knife, while nephrite resists the knife and scratches glass.
What does nephrite look like?
It is a smooth, greasy-lustered, translucent-to-opaque stone in greens, creamy white, grey, or black, usually massive with no visible crystals and often found as polished river boulders.
Nephrite identified by the community
Recent Nephrite specimens identified with Rock Identifier.
