from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. Gypsum in the form of colorless clear crystals.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A soft, glassy form of gypsum (chemical formula CaSO4·2H2O).
  • n. The anion SeO32− derived from selenous acid; any salt or ester of selenous acid.

from the GNU version of the Collaborative International Dictionary of English

  • n. A salt of selenious acid.
  • n. A variety of gypsum, occuring in transparent crystals or crystalline masses.

from The Century Dictionary and Cyclopedia

  • n. [capitalized] A supposed inhabitant of the moon.
  • n. A foliated or crystallized and transparent variety of gypsum, often obtained in large thin plates somewhat resembling mica; also, specifically, a thin plate of this mineral used with the polarizing apparatus of the microscope.
  • n. In chem., a salt of selenium.


Latin selēnītēs, from Greek selēnītēs (lithos), moon (stone), selenite (so called because it was believed to wax and wane with the moon), from selēnē, moon; see selenium.
(American Heritage® Dictionary of the English Language, Fourth Edition)



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  • Selenite, satin spar, desert rose, and gypsum flower are the four crystalline varieties of gypsum.

    February 14, 2008