COMPARE GUIDE
Purple GlassVSSynthetic Purple Sapphire
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Decisive distinctionsDECISIVE
- ◎ is higher in Synthetic Purple Sapphire, giving a numerical distinguishing point.
- ◎ is higher in Synthetic Purple 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: Purple Glass | B: Synthetic Purple Sapphire | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.480–1.700 | 1.762–1.770 | B higher |
| Specific gravity (SG) | 2.30–4.50 | 3.98–4.05 | Overlap |
| Mohs hardness | 5.0–6.0 | 9.0 | B higher |
| Birefringence | — | 0.008 | — |
| Dispersion | — | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Purple Glass | B: Synthetic Purple Sapphire |
|---|---|---|
| Crystal system | 非晶質 | 六方晶系（三方晶系） |
| Pleochroism | — | 中〜強（紫・赤紫） |
| Chelsea filter | — | — |
| UV (long-wave) | — | — |
| UV (short-wave) | inert | medium (red) |
ObservationOBSERVATION
◆Purple glass typically has RI ~1.50, SG 2.4–3.0, isotropic, with gas bubbles and . Synthetic purple sapphire has RI 1.760–1.770, weak , and Mohs 9 — refractometer-distinct.
Color categoriesCATEGORIES
A: Purple Glass
Purple
B: Synthetic Purple Sapphire
Purple
DISTINGUISHING TOOLS · 3 ITEMS
Distinguishing tools
Tools that decide between Purple Glass and Synthetic Purple 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.