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Cubic ZirconiaVSNatural White Sapphire
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
- ◎ is higher in Cubic Zirconia, giving a numerical distinguishing point.
- ◎ is higher in Cubic Zirconia, giving a numerical distinguishing point.
- ◎ is higher in Natural White Sapphire, 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.
| Property | A: Cubic Zirconia | B: Natural White Sapphire | Verdict |
|---|---|---|---|
| Refractive index (RI) | 2.150–2.180 | 1.762–1.770 | A higher |
| Specific gravity (SG) | 5.50–6.00 | 3.95–4.03 | A higher |
| Mohs hardness | 8.0–8.5 | 9.0 | B higher |
| Birefringence | — | 0.008 | — |
| Dispersion | 0.060 | — | — |
| Property | A: Cubic Zirconia | 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) | weak (yellow) | inert |
| UV (short-wave) | weak (yellow) | weak (white) |
◆Natural white sapphire (Al₂O₃, RI 1.762–1.770, SG 4.00, 0.018, Mohs 9) is significantly lighter than CZ and has dramatically lower — fire is muted rather than rainbow-bright. Doubly refractive (visible at 30× through the table); CZ is singly refractive. White sapphire's Mohs 9 makes it more scratch-resistant than CZ's 8.0–8.5.
Distinguishing tools
Tools that decide between Cubic Zirconia 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.