COMPARE GUIDE
Imperial TopazVSOrange Sapphire / Padparadscha
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Decisive distinctionsDECISIVE
- ◎ is higher in Orange Sapphire / Padparadscha, giving a numerical distinguishing point.
- ◎ is higher in Orange Sapphire / Padparadscha, giving a numerical distinguishing point.
- ◎ is higher in Orange Sapphire / Padparadscha, giving a numerical distinguishing point.
- ◎ is higher in Imperial Topaz, 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: Imperial Topaz | B: Orange Sapphire / Padparadscha | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.629–1.638 | 1.762–1.770 | B higher |
| Specific gravity (SG) | 3.50–3.57 | 3.95–4.03 | B higher |
| Mohs hardness | 8.0 | 9.0 | B higher |
| Birefringence | 0.010 | 0.008 | A higher |
| Dispersion | — | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Imperial Topaz | B: Orange Sapphire / Padparadscha |
|---|---|---|
| Crystal system | 斜方晶系 | 六方晶系（三方晶系） |
| Pleochroism | 強（黄・赤・ピンク） | 中（オレンジ・黄オレンジ） |
| Chelsea filter | inert | — |
| UV (long-wave) | weak (yellow / orange) | — |
| UV (short-wave) | inert | weak (orange) |
ObservationOBSERVATION
◆Imperial topaz is Mohs 8 with a perfect basal and lower density (SG 3.55); orange sapphire is Mohs 9 with no and SG 4.0.
Color categoriesCATEGORIES
A: Imperial Topaz
Yellow / orange
B: Orange Sapphire / Padparadscha
Yellow / orange
DISTINGUISHING TOOLS · 3 ITEMS
Distinguishing tools
Tools that decide between Imperial Topaz and Orange Sapphire / Padparadscha 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.