| physico-chemical properties | titaniferous sand | calcium silicate |
| pH | 6.4 | 12.3 |
| pHpzc | 8.75 | 9.2 |
| Absolute density (kg/m3) | 4054 | 1980 |
| Bulk density (kg/m3) | 2500 | 400 |
| Porosity (%) | 38 | 79 |
| Specific surface (m2/g) | 13.4 | 314.2 |