COMPARE GUIDE
Natural Blue SapphireVSSynthetic Blue Sapphire
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Physical propertiesPROPERTIES
| Property | A: Natural Blue Sapphire | B: Synthetic Blue Sapphire | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.762–1.770 | 1.762–1.770 | Nearly equal |
| Specific gravity (SG) | 3.95–4.03 | 3.98–4.05 | Overlap |
| Mohs hardness | 9.0 | 9.0 | Nearly equal |
| Birefringence | 0.008 | 0.008 | Nearly equal |
| Dispersion | — | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Natural Blue Sapphire | B: Synthetic Blue Sapphire |
|---|---|---|
| Crystal system | 六方晶系（三方晶系） | 六方晶系（三方晶系） |
| Pleochroism | 強（青・緑青） | 強（青・緑青） |
| Chelsea filter | inert | inert |
| UV (long-wave) | inert | weak (blue / green) |
| UV (short-wave) | inert | medium (green) |
ObservationOBSERVATION
◆nclusions, and natural color zoning absent in flame-fusion synthetics; hydrothermal synthetics from Tairus can mimic Kashmir natural sapphire visually and require LA-ICP-MS lab analysis for definitive identification.
Color categoriesCATEGORIES
A: Natural Blue Sapphire
Blue
B: Synthetic Blue Sapphire
Blue
DISTINGUISHING TOOLS · 3 ITEMS
Distinguishing tools
Tools that decide between Natural Blue Sapphire and Synthetic Blue Sapphire 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.