COMPARE GUIDE
Black SpinelVSMelanite Garnet
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Decisive distinctionsDECISIVE
- ◎ is higher in Melanite Garnet, giving a numerical distinguishing point.
- ◎ is higher in Black 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.
Physical propertiesPROPERTIES
| Property | A: Black Spinel | B: Melanite Garnet | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.712–1.736 | 1.855–1.895 | B higher |
| Specific gravity (SG) | 3.58–3.90 | 3.70–3.90 | Overlap |
| Mohs hardness | 8.0 | 6.5–7.0 | A higher |
| Birefringence | — | — | — |
| Dispersion | — | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Black Spinel | B: Melanite Garnet |
|---|---|---|
| Crystal system | 等軸晶系 | 等軸晶系 |
| Pleochroism | — | — |
| Chelsea filter | — | — |
| UV (long-wave) | — | — |
| UV (short-wave) | inert | inert |
ObservationOBSERVATION
◆Black spinel shows very little (no rainbow fire) and is lighter (SG 3.60); melanite shows diamond-rivaling rainbow flashes and is denser (SG 3.85).
Color categoriesCATEGORIES
A: Black Spinel
Black / gray
B: Melanite Garnet
Black / gray
DISTINGUISHING TOOLS · 2 ITEMS
Distinguishing tools
Tools that decide between Black Spinel and Melanite Garnet 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.