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HeliodorVSYellow Topaz
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Decisive distinctionsDECISIVE
- ◎ is higher in Yellow Topaz, giving a numerical distinguishing point.
- ◎ is higher in Yellow Topaz, giving a numerical distinguishing point.
- ◎ is higher in Yellow 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: Heliodor | B: Yellow Topaz | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.566–1.594 | 1.629–1.638 | B higher |
| Specific gravity (SG) | 2.66–2.87 | 3.50–3.57 | B higher |
| Mohs hardness | 7.5–8.0 | 8.0 | Overlap |
| Birefringence | 0.005 | 0.010 | B higher |
| Dispersion | — | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Heliodor | B: Yellow Topaz |
|---|---|---|
| Crystal system | 六方晶系 | 斜方晶系 |
| Pleochroism | 弱〜中（黄・無色） | 中（黄・無色） |
| Chelsea filter | inert | inert |
| UV (long-wave) | inert | weak (yellow / orange) |
| UV (short-wave) | inert | inert |
ObservationOBSERVATION
◆Yellow topaz has dramatically higher SG (~3.5) and feels noticeably heavy in hand at equal size; shows stronger dichroism.
Color categoriesCATEGORIES
A: Heliodor
Yellow / orange
B: Yellow Topaz
Yellow / orange
DISTINGUISHING TOOLS · 3 ITEMS
Distinguishing tools
Tools that decide between Heliodor and Yellow Topaz 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.