

| CHEMISTRY - Elbbaite, Na(Li,Al)3Al6B3Si6O27(OH)3(OH,F) |
| CRYSTALLOGRAPHY - Hexxagonal |
| REFRACTIVE INDEX - 1.603 - 1.655 |
| HARDNESS - 7 -- 7.5 |
| SPECIFIC GRAVITY - 2.84 - 3.10 |
| CLEAVAGE - No |
| HEAT SENSITIVE - Some |
| WEARABILITY - Very Good |
| SPECIAL CARE INSTRUCTIONS - Multicolored gems are often weak where the colors meet |
| ENHANCEMENTS - Heat treatment, common on dark gems, otherwise occasional. Irridation, occasional. |
