COMPARE GUIDE
Brown SapphireVSDravite (Brown Tourmaline)
Side-by-side comparison of physical properties, fluorescence, and crystal system — to identify by observation.
Decisive distinctionsDECISIVE
- ◎ is higher in Brown Sapphire, giving a numerical distinguishing point.
- ◎ is higher in Brown Sapphire, giving a numerical distinguishing point.
- ◎ is higher in Brown Sapphire, giving a numerical distinguishing point.
- ◎ is higher in Dravite (Brown Tourmaline), 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: Brown Sapphire | B: Dravite (Brown Tourmaline) | Verdict |
|---|---|---|---|
| Refractive index (RI) | 1.762–1.770 | 1.624–1.644 | A higher |
| Specific gravity (SG) | 3.95–4.03 | 3.04–3.20 | A higher |
| Mohs hardness | 9.0 | 7.0–7.5 | A higher |
| Birefringence | 0.008 | 0.018 | B higher |
| Dispersion | — | — | — |
Optics & fluorescenceOPTICS & UV
| Property | A: Brown Sapphire | B: Dravite (Brown Tourmaline) |
|---|---|---|
| Crystal system | 六方晶系（三方晶系） | 三方晶系 |
| Pleochroism | 中（茶・黄茶） | 強（茶・黄茶） |
| Chelsea filter | — | — |
| UV (long-wave) | — | — |
| UV (short-wave) | inert | inert |
ObservationOBSERVATION
◆Brown sapphire has RI 1.76+ and SG 3.99 with weak ; dravite has RI 1.62–1.64 and SG 3.04–3.20 with strong nclusions.
Color categoriesCATEGORIES
A: Brown Sapphire
Brown
B: Dravite (Brown Tourmaline)
Brown
DISTINGUISHING TOOLS · 3 ITEMS
Distinguishing tools
Tools that decide between Brown Sapphire and Dravite (Brown Tourmaline) 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.