COMPARE GUIDE
Natural AlexandriteVSSynthetic Alexandrite (Pulled / Verneuil)
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Physical propertiesPROPERTIES
| Property | A: Natural Alexandrite | B: Synthetic Alexandrite (Pulled / Verneuil) | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.745–1.755 | 1.745–1.755 | Nearly equal |
| Specific gravity (SG) | 3.71–3.75 | 3.71–3.75 | Nearly equal |
| Mohs hardness | 8.5 | 8.5 | Nearly equal |
| Birefringence | 0.009 | 0.009 | Nearly equal |
| Dispersion | — | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Natural Alexandrite | B: Synthetic Alexandrite (Pulled / Verneuil) |
|---|---|---|
| Crystal system | 斜方晶系 | 斜方晶系 |
| Pleochroism | 強（緑・赤紫・黄橙） | — |
| Chelsea filter | red | red |
| UV (long-wave) | weak (red) | strong (red) |
| UV (short-wave) | weak (red) | strong (red) |
ObservationOBSERVATION
◆nclusions, and natural color zoning absent in flame-fusion or pulled synthetics; SG and RI match genuine synthetic chrysoberyl but not the V-doped corundum substitute, which has higher SG (4.0 vs. 3.73) and RI.
Color categoriesCATEGORIES
A: Natural Alexandrite
Color-change
B: Synthetic Alexandrite (Pulled / Verneuil)
Color-change
DISTINGUISHING TOOLS · 3 ITEMS
Distinguishing tools
Tools that decide between Natural Alexandrite and Synthetic Alexandrite (Pulled / Verneuil) 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.