COMPARE GUIDE
Blue Spinel (Natural)VSSynthetic Blue Spinel
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
- ◎ is higher in Synthetic Blue Spinel, 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: Blue Spinel (Natural) | B: Synthetic Blue Spinel | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.712–1.736 | 1.727–1.731 | Overlap |
| Specific gravity (SG) | 3.58–3.61 | 3.62–3.65 | B higher |
| Mohs hardness | 8.0 | 8.0 | Nearly equal |
| Birefringence | — | — | — |
| Dispersion | — | — | — |
| Property | A: Blue Spinel (Natural) | B: Synthetic Blue Spinel |
|---|---|---|
| Crystal system | 等軸晶系 | 等軸晶系 |
| Pleochroism | — | — |
| Chelsea filter | inert | red |
| UV (long-wave) | inert | weak (blue / white) |
| UV (short-wave) | inert | strong (white) |
◆nclusions.
Distinguishing tools
Tools that decide between Blue Spinel (Natural) and Synthetic Blue Spinel in practice.
- Chelsea filterDETAILS →
Quick chrome-content screen — chromium-bearing stones glow red through the filter
- UV lamp (short-wave 254 nm)DETAILS →
Short-wave UV reveals white fluorescence (strong) — a decisive synthetic-vs-natural cue
- Handheld spectroscopeDETAILS →
Absorption-line pattern identifies the chromophore (Cr, Fe, or Co)
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.