noun Date: 1937 any of a group of hydrous silicates of aluminum and sometimes other metals formed chiefly in weathering processes and occurring especially in clay and shale
CLAY MINERAL
Meaning of CLAY MINERAL in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012