COMPARE GUIDE
Natural AmethystVSSynthetic Amethyst
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Physical propertiesPROPERTIES
| Property | A: Natural Amethyst | B: Synthetic Amethyst | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.544–1.553 | 1.544–1.553 | Nearly equal |
| Specific gravity (SG) | 2.64–2.66 | 2.64–2.66 | Nearly equal |
| Mohs hardness | 7.0 | 7.0 | Nearly equal |
| Birefringence | 0.009 | 0.009 | Nearly equal |
| Dispersion | — | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Natural Amethyst | B: Synthetic Amethyst |
|---|---|---|
| Crystal system | 三方晶系 | 三方晶系 |
| Pleochroism | 弱（紫・赤紫） | 弱（紫・赤紫） |
| Chelsea filter | inert | inert |
| UV (long-wave) | inert | inert |
| UV (short-wave) | inert | inert |
ObservationOBSERVATION
◆Hydrothermal synthetics lack tiger-stripe zoning and are too clean. Lab spectroscopy or specific gravity matching is the practical test.
Color categoriesCATEGORIES
A: Natural Amethyst
Purple
B: Synthetic Amethyst
Purple
DISTINGUISHING TOOLS · 2 ITEMS
Distinguishing tools
Tools that decide between Natural Amethyst and Synthetic Amethyst in practice.
Note: this page is auto-generated from published GIA / CGL reference values. Individual stones, treatments, and synthetics may fall outside these ranges. For a definitive identification, consult an accredited gem laboratory.