Jadeite vs Nephrite: How to Tell Them Apart
Both jadeite and nephrite are commercially called "jade," but they are different minerals with different compositions, different crystal structures, and measurably different properties. SG is the most practical field test: jadeite is substantially heavier. Their RI ranges also separate cleanly, and their internal textures differ under magnification.
Property Comparison
| Property | Jadeite | Nephrite | Diagnostic? |
|---|---|---|---|
| RI | 1.654 – 1.688 | 1.600 – 1.627 | Yes |
| SG | 3.24 – 3.43 | 2.90 – 3.03 | Yes |
| Hardness | 6.5 – 7 | 6 – 6.5 | No |
| Crystal System | Aggregate | Aggregate | No |
| Optic Character | AGG | AGG | No |
| Birefringence | N/A (aggregate) | N/A (aggregate) | No |
| Fluorescence (LW) | Inert | Inert | No |
| Chelsea Filter | Variable (Cr-green may show red) | Inert | No |
| Pleochroism | None (aggregate) | None (aggregate) | No |
The Definitive Tests
- SG measurement — the most practical test. Jadeite SG 3.24-3.43 vs nephrite SG 2.90-3.03. The ranges do not overlap. For carvings and larger pieces, hydrostatic weighing is straightforward and definitive. Jadeite feels noticeably heavier in hand for the same volume.
- Spot RI reading (polished surface). Using the spot method on a flat polished surface: jadeite reads approximately 1.66, nephrite reads approximately 1.61. The separation is clear, though spot readings on aggregate materials require care.
- Surface texture under magnification. Jadeite shows an interlocking granular texture — polished surfaces often display a "dimpled" or "orange-peel" effect visible under 10x loupe. Nephrite shows a fibrous, felted texture — individual fibers are sometimes visible at the surface as fine parallel lines.
Common Mistakes
- Assuming all green jade is jadeite. Both jadeite and nephrite come in green. Nephrite jade has been used in China for thousands of years before jadeite was introduced from Myanmar in the 18th century. Green alone tells you nothing about the species.
- Ignoring treatment in jadeite. Jadeite is commonly treated: "B jade" is bleached and polymer-impregnated, "C jade" is dyed. These treatments affect appearance and value but do not change the jadeite-vs-nephrite species identification. Treatment detection is a separate question from species identification.
- Forgetting serpentine and other simulants. Many materials are sold as "jade" — serpentine (bowenite), aventurine quartz, prehnite, and hydrogrossular garnet are all common jade simulants. SG testing separates them all: serpentine reads 2.5-2.6, lower than both jadeite and nephrite.
Frequently Asked Questions
Are jadeite and nephrite both real jade?
Yes. Both are accepted as "jade" in the gem trade and by gemological laboratories. However, they are distinct minerals: jadeite is a pyroxene (NaAlSi2O6) and nephrite is an amphibole (actinolite-tremolite). They differ in RI, SG, and internal structure.
Is jadeite more valuable than nephrite?
Generally, yes. Fine jadeite — especially "Imperial jade" (vivid green, translucent, untreated) from Myanmar — commands the highest prices of any jade. Nephrite is more abundant and generally less expensive, though fine mutton-fat white nephrite and certain New Zealand greenstone pieces are highly valued in their own right.
Can you tell jadeite from nephrite by color?
Not reliably. Both come in green, and their color ranges overlap. Jadeite occurs in a wider range of colors (including lavender, orange, black, and white), but green examples of both can look identical. SG testing (jadeite 3.24-3.43, nephrite 2.90-3.03) is the most practical separation method.
Identifying jade? GemID walks you through SG measurement and species identification step by step.
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