Earth

Name:
Earth
Detailed information:
(1) Any siliceous or claylike compound or mixture, e.g., fuller's earth, diatomaceous earth. (2) A natural metallic oxide, sometimes used as a pigment, e.g., red and yellow iron oxide, ocher, or umber. (3) An oxide of any of a series of chemically related metals that are difficult to separate from their oxides or other combined forms, specifically, rare earths, alkaline earths.See specific entry.