| Other names: | Clay |
| Mineral class: | Phyllosilicate |
| Composition: | Hydrous alumino-silicates. Na0.3Al2(Si3.7Al0.3)O10(OH)2 |
| Hardness: | 1.5 - 2.5 |
| Streak: | White |
| Environment: | Forms from weathering (partial hydrolysis) of micas and amphiboles in dry, cool climates. |
| Comments: | Highly absorbent, used in cat litter. Also used to filter impurities from beer and wine. |