| Property | Specification |
| Appearance | Black, lightweight, porous solid |
| Shape | Irregular lumps, powder, or briquettes |
| Color | Dark black or grayish-black |
| Size | Varies from small granules to large lumps |
| Density | 0.2 to 0.5 g/cm³ |
| Hardness | Varies, typically medium to hard |
| Moisture Content | Less than 5% |
| Ash Content | 5% to 15% |
| Volatile Matter | 20% to 30% |
| Fixed Carbon Content | 70% to 80% |
| Porosity | High |
| Thermal Conductivity | Low (insulating material) |
| Combustion Temperature | 600°C to 900°C |
| Specific Heat Capacity | 0.25 to 0.3 J/g°C |