COMPARE GUIDE
Natural Pink SapphireVSPink Spinel
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Decisive distinctionsDECISIVE
- ◎ is higher in Natural Pink Sapphire, giving a numerical distinguishing point.
- ◎ is higher in Natural Pink Sapphire, giving a numerical distinguishing point.
- ◎ is higher in Natural Pink 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.
Physical propertiesPROPERTIES
| Property | A: Natural Pink Sapphire | B: Pink Spinel | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.762–1.770 | 1.712–1.736 | A higher |
| Specific gravity (SG) | 3.95–4.03 | 3.58–3.61 | A higher |
| Mohs hardness | 9.0 | 8.0 | A higher |
| Birefringence | 0.008 | — | — |
| Dispersion | — | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Natural Pink Sapphire | B: Pink Spinel |
|---|---|---|
| Crystal system | 六方晶系(三方晶系) | 等軸晶系 |
| Pleochroism | 弱〜中(ピンク・淡ピンク) | — |
| Chelsea filter | pink / red | red / pink |
| UV (long-wave) | medium (red) | weak (red) |
| UV (short-wave) | weak (red) | weak (red) |
ObservationOBSERVATION
◆Spinel is singly refractive with no dichroism. A polariscope or dichroscope separates them in seconds.
Color categoriesCATEGORIES
A: Natural Pink Sapphire
Red / pink
B: Pink Spinel
Red / pink
DISTINGUISHING TOOLS · 3 ITEMS
Distinguishing tools
Tools that decide between Natural Pink Sapphire and Pink Spinel 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.

