| Color | Brown |
| Crystal form | T rigonal system |
| Hardness ( Mohs ) | ≥9.0 |
| Melting Point (ºC) | 2050 |
| High Dislocation temperature (ºC) | 1800 |
| True density (g/cm3) | ≥3.9 |
| S ize | B.D.(g/cm 3 ) | S ize | B.D.(g/cm 3 ) | S ize | B.D.(g/cm 3 ) |
| 12 | 2.02-2.10 | 36 | 90 | 1.64-1.76 | |
| 14 | 2.00-2.07 | 40 | 1.83-1.93 | 100 | 1.62-1.74 |
| 16 | 1.97-2.04 | 46 | 1. 7 6-1.88 | 120 | 1.61-1.73 |
| 20 | 1.96-2.02 | 54 | 1.75-1.87 | 150 | 1.60-1.72 |
| 22 | 1.95-2.01 | 60 | 1.70-1.82 | 180 | 1.58-1.68 |
| 24 | 1.90-2.00 | 70 | 1.68-1.80 | 220 | 1.56-1.67 |
| 30 | 1.88-1.98 | 80 | 1.66-1.78 | 240 | 1. 56 -1.72 |
| Specification | Chemical Composition(%) | Magnetic material content(%) | ||||
| Al 2 O 3 | Fe 2 O 3 | SiO 2 | TiO 2 | |||
| F | 12#-80# | ≥95.5 | ≤0.2 | ≤1.0 | 2.2-3.0 | ≤0.02 |
| 90#-150# | ≥95 | ≤0.02 | ||||
| 180#-240# | ≥94.5 | ≤0.3 | ≤1.2 | 2.2-3.0 | ≤0.02 | |