COMPARE GUIDE
Natural DiamondVSNatural White Sapphire
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Decisive distinctionsDECISIVE
- ◎ is higher in Natural Diamond, giving a numerical distinguishing point.
- ◎ is higher in Natural White Sapphire, giving a numerical distinguishing point.
- ◎ is higher in Natural Diamond, giving a numerical distinguishing point.
Note: properties whose numeric ranges do not overlap are auto-extracted. Both are measurable with a refractometer or heavy-liquid bath.
Physical propertiesPROPERTIES
| Property | A: Natural Diamond | B: Natural White Sapphire | Verdict |
|---|---|---|---|
| Refractive index (RI) | 2.417–2.419 | 1.762–1.770 | A higher |
| Specific gravity (SG) | 3.50–3.53 | 3.95–4.03 | B higher |
| Mohs hardness | 10.0 | 9.0 | A higher |
| Birefringence | — | 0.008 | — |
| Dispersion | 0.044 | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Natural Diamond | B: Natural White Sapphire |
|---|---|---|
| Crystal system | 等軸晶系 | 六方晶系（三方晶系） |
| Pleochroism | — | — |
| Chelsea filter | inert | inert |
| UV (long-wave) | medium (blue) | inert |
| UV (short-wave) | inert | weak (white) |
ObservationOBSERVATION
◆nclusions when present.
Color categoriesCATEGORIES
A: Natural Diamond
Colorless
B: Natural White Sapphire
Colorless
DISTINGUISHING TOOLS · 3 ITEMS
Distinguishing tools
Tools that decide between Natural Diamond and Natural White 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.