An Etymological Dictionary of Astronomy and Astrophysics

A broad class of hydrous → silicate minerals that has the tetrahedral silicate groups linked in sheets. Clay commonly forms as a product of rock weathering. Deposits of phyllosilicates, such as chamosite and nontronite, recently identified on Mars are attributed to the action of liquid water in the past history of this planet.

Etymology (EN): O.E. clæg “stiff, sticky earth; clay,” from PIE base *glei- “to stick together;” cf. Gk. gloios “sticky substance,” L. glus, gluten “glue,” O.Slav. glina “clay.” The Pers. gel “clay, mud,” Mid.Pers. gil “clay” may belong to this family.

Etymology (PE): Ros, variant rost “clay,” of unknown origin.