COMPARE GUIDE
Natural Yellow SapphireVSYellow Zircon
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Decisive distinctionsDECISIVE
- ◎ is higher in Yellow Zircon, giving a numerical distinguishing point.
- ◎ is higher in Yellow Zircon, giving a numerical distinguishing point.
- ◎ is higher in Natural Yellow Sapphire, giving a numerical distinguishing point.
- ◎ is higher in Yellow Zircon, 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 Yellow Sapphire | B: Yellow Zircon | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.762–1.770 | 1.925–1.984 | B higher |
| Specific gravity (SG) | 3.95–4.03 | 4.60–4.80 | B higher |
| Mohs hardness | 9.0 | 7.0–7.5 | A higher |
| Birefringence | 0.008 | 0.039 | B higher |
| Dispersion | — | 0.039 | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Natural Yellow Sapphire | B: Yellow Zircon |
|---|---|---|
| Crystal system | 六方晶系（三方晶系） | 正方晶系 |
| Pleochroism | 弱〜中（黄・淡黄） | — |
| Chelsea filter | inert | inert |
| UV (long-wave) | weak (orange / yellow) | weak (yellow) |
| UV (short-wave) | weak (yellow) | weak (yellow) |
ObservationOBSERVATION
◆Yellow sapphire has RI 1.76–1.77 and SG 4.0, with much weaker (no rainbow fire) and no . Yellow zircon has RI 1.92–2.01 and SG 4.6–4.7 with strong and pronounced rainbow fire.
Color categoriesCATEGORIES
A: Natural Yellow Sapphire
Yellow / orange
B: Yellow Zircon
Yellow / orange
DISTINGUISHING TOOLS · 3 ITEMS
Distinguishing tools
Tools that decide between Natural Yellow Sapphire and Yellow Zircon 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.