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Pink GlassVSNatural Pink Sapphire
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
- ◎ 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.
| Property | A: Pink Glass | B: Natural Pink Sapphire | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.480–1.700 | 1.762–1.770 | B higher |
| Specific gravity (SG) | 2.30–4.50 | 3.95–4.03 | Overlap |
| Mohs hardness | 5.0–6.0 | 9.0 | B higher |
| Birefringence | — | 0.008 | — |
| Dispersion | — | — | — |
| Property | A: Pink Glass | B: Natural Pink Sapphire |
|---|---|---|
| Crystal system | 非晶質 | 六方晶系（三方晶系） |
| Pleochroism | — | 弱〜中（ピンク・淡ピンク） |
| Chelsea filter | — | pink / red |
| UV (long-wave) | — | medium (red) |
| UV (short-wave) | inert | weak (red) |
◆Natural pink sapphire (Al₂O₃ corundum colored by trace chromium, Mohs 9, SG 3.99–4.01, RI 1.762–1.770, doubly refractive, 0.018) differs from pink glass by a wide margin on every measurable parameter. Refractometer reads 1.762–1.770 for sapphire versus 1.50–1.70 for glass — clean diagnostic separation. Polariscope: pink sapphire doubly refractive, glass singly refractive. Mohs 9 sapphire is unaffected by a steel-knife scratch test that easily marks Mohs 5–6 glass. Specific gravity 3.99–4.01 (sapphire) versus 2.4–4.5 (glass) gives noticeable hand-heft difference at 1 ct and above. Pink sapphire shows characteristic natural silk (short rutile needles in three crystallographic directions) and hexagonal color zoning at 10×; glass shows regular round gas bubbles and pressing-die seams. The Madagascar Ilakaka (1998 discovery) and Burmese Mogok deposits supply the high-grade natural pink sapphire that pink glass most often imitates. Disclosure as 'glass' or 'imitation pink sapphire' is required under FTC Jewelry Guides §23.25.
Distinguishing tools
Tools that decide between Pink Glass and Natural Pink 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.