Jadeite vs Serpentine: How to Tell Them Apart
Last updated: August 2026
Serpentine is the most common jade simulant in the trade — sold as "new jade", "Korean jade", "Suzhou jade", or simply as jade. Its massive habit, waxy to greasy luster, and green color superficially mimic both jadeite and nephrite. The good news for rockhounds: this is one of the easiest separations in gemology. Serpentine is softer (Mohs 3-6 vs jadeite's 6.5-7), much lighter (SG 2.44-2.62 vs 3.24-3.43), and reads far lower on the refractometer. If you are separating the two true jades from each other instead, see jadeite vs nephrite.
Property Comparison
| Property | Jadeite | Serpentine | Diagnostic? |
|---|---|---|---|
| Hardness | 6.5 – 7 | 3 – 6 | Yes |
| SG | 3.24 – 3.43 | 2.44 – 2.62 | Yes |
| RI | 1.654 – 1.688 | 1.560 – 1.571 | Yes |
| Luster | Vitreous to waxy | Waxy to silky | No |
| Optic Character | AGG | AGG | No |
| Fluorescence (LW) | Inert | Inert | No |
| Chelsea Filter | Variable (Cr-green may show red) | Inert | No |
| Texture (10x) | Interlocking blocky granular; dimpled "orange-peel" polished surface | Fibrous or mottled | No |
| Pleochroism | None (aggregate) | None (aggregate) | No |
The Definitive Tests
Rockhound checklist order — start with the cheap destructive-adjacent tests on rough or an inconspicuous spot, and leave the refractometer for last.
- Scratch test — a steel knife blade is a fast first screen. Most serpentine (Mohs 3-6) is scratched by a steel knife blade; jadeite (Mohs 6.5-7) is not. A stone that scratches is not jadeite — but the hardest serpentine approaches blade hardness, so confirm an unscratched stone with SG or RI. Never scratch a polished display surface — pick a hidden spot.
- SG / heft test. Serpentine SG 2.44-2.62 is notably lighter than jadeite's 3.24-3.43 — jadeite is roughly 25% heavier for the same volume. An experienced heft test detects this by hand; hydrostatic weighing makes it definitive. The ranges do not overlap.
- RI — the confirming instrument test. Serpentine reads 1.560-1.571 — dramatically lower than jadeite (1.654-1.688) and also below nephrite (1.600-1.627). A spot reading on a polished surface makes refractometer testing definitive: jadeite reads approximately 1.66, serpentine approximately 1.56-1.57.
Common Mistakes
- Trusting trade names. "New jade", "Korean jade", and "Suzhou jade" are serpentine, not jade. Any qualifier in front of the word "jade" is a red flag — verify with hardness, SG, or RI rather than the label.
- Relying on luster and color. Serpentine's waxy luster and green body color are exactly why it works as a jade impostor. Under the loupe serpentine tends to show a fibrous or mottled texture, while jadeite shows an interlocking granular texture with a dimpled "orange-peel" polished surface — but texture takes practice to read. Hardness and SG do not.
- Stopping at "it's not serpentine." Passing the scratch test does not make a stone jadeite — nephrite (Mohs 6-6.5, SG 2.90-3.03) also resists a knife blade. Once serpentine is excluded, run the jadeite vs nephrite separation. Note serpentine is also commonly dyed (green, lavender) or wax-impregnated to improve luster — treatments that make it look even more jade-like.
Frequently Asked Questions
Is serpentine real jade?
No. Serpentine is the most common jade simulant in the trade, sold as "new jade", "Korean jade", "Suzhou jade", or simply as jade. Its massive habit, waxy to greasy luster, and green color superficially mimic both jadeite and nephrite, but it is a different mineral with lower hardness (Mohs 3-6), SG (2.44-2.62), and RI (1.560-1.571).
Will a knife scratch jade?
Usually not. Jadeite is Mohs 6.5-7, well above a steel blade. Most serpentine (Mohs 3-6) is scratched by a steel blade, though the hardest material approaches blade hardness — a stone the blade cannot scratch still needs SG or RI to confirm jadeite. Test an inconspicuous spot (the base of a carving, never a polished display surface).
How heavy is jadeite compared to serpentine?
Jadeite (SG 3.24-3.43) is roughly 25% heavier than serpentine (SG 2.44-2.62) for the same volume. An experienced heft test detects this immediately, and hydrostatic weighing confirms it — the SG ranges do not come close to overlapping.
Checking a suspected jade? Loupewise walks you through hardness, SG, and RI testing step by step.
Open Loupewise →Studying for a gemology practical? Loupewise’s timed exam simulators drill exactly this call — separating look-alike stones by their measured properties.
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