| Composition | Ech. BN 01 | Ech. BN 04 | Ech. BN 05 |
| SiO2 | 64.61 | 50.83 | 20.66 |
| TiO2 | 1.92 | 0.35 | 0.32 |
| Al2O3 | 4.40 | 4.07 | 3.53 |
| Fe2 O3 | 0.99 | 1.83 | 2.53 |
| MnO | 0.02 | 0.02 | 0.09 |
| MgO | 0.00 | 3.58 | 2.91 |
| CaO | 0.35 | 5.78 | 14.31 |
| Na2O | 0.00 | 0.00 | 0.28 |
| K2O | 2.00 | 2.23 | 0.83 |
| P2O5 | 0.02 | 0.05 | 0.08 |
| LOI | 25.70 | 31.27 | 54.45 |