geode n.

Earth as a goddess, from Greek Gaia, spouse of Uranus, mother of the Titans, personification of gaia "earth" (as opposed to heaven), "land" (as opposed to sea), "a land, country, soil;" it is a collateral form of gē (Dorian ga) "earth," which is of unknown origin and perhaps from a pre-Indo-European language of Greece. The Roman equivalent goddess of the earth was Tellus (see tellurian), sometimes used in English poetically or rhetorically for "Earth personified" or "the Earth as a planet."

word-forming element meaning "like, like that of, thing like a ______," from Latinized form of Greek -oeidēs (three syllables), from eidos "form," related to idein "to see," eidenai "to know;" literally "to see" (from PIE *weid-es-, from root *weid- "to see"). The -o- is connective or a stem vowel from the previous element. Often implying an incomplete or imperfect resemblance to the thing indicated.