| Phase (%) | Formule | Clay samples | |||||
| YC1 | YC2 | RC1 | RC2 | LC1 | LC2 | ||
| Quartz | SiO2 | 30.7 | 30.1 | 68 | 67.3 | 20.4 | 20.1 |
| Muscovite | KAl2AlSi3O8(OH)2 | 3.0 | 2.9 | 2 | 2.3 | 3.1 | 3.0 |
| Kaolinite | Al2Si2O5(OH)4 | 36.4 | 37.5 | 25.4 | 26.2 | 31.6 | 30.5 |
| Illite | (K∙H3O)(Al∙Mg∙Fe)2(Si∙Al)4O10[(OH)2∙(H2O)] | 15.6 | 15.3 | - | - | - | - |
| Goethite | FeOOH | 4.3 | 4.2 | 3.3 | 4.2 | 27.8 | 28.7 |
| Hematite | Fe2O3 | 0.4 | 0.3 | - | - | 3.2 | 3.1 |
| Amorphes | 9.6 | 9.7 | - | - | 13.9 | 14.6 | |
| Total |
| 100 | 100 | 98.7 | 100 | 100 | 100 |