selenite

From Ancient Greek σελήνη (selḗnē, “moon”) +‎ -ite; the chemistry sense comes via the name of the element selenium.

• IPA^(key): /ˈsɛlɪnaɪt/

selenite (countable and uncountable, plural selenites)

1. (mineralogy) A soft, glassy form of gypsum (chemical formula CaSO₄·2H₂O).
   • 1898, H.G. Wells, The War of the Worlds, London: William Heinemann, page 295:

     I followed them to my study, and found lying on my writing-table still, with the selenite paper-weight upon it, the sheet of work I had left on the afternoon of the opening of the cylinder.

   • 1994, Stewart Brand, How Buildings Learn: What Happens After They’re Built, New York: Viking, →ISBN, page 146:

     Glass windows replaced the old tiny windows of selenite (crystallized gypsum), and stovepipe replaced adobe chimneys.

2. (inorganic chemistry) The anion SeO₃²⁻ derived from selenous acid; any salt or ester of selenous acid.

• satin spar (1)

• cadmium selenite
• silver selenite
• sodium selenite

• David Barthelmy (1997–2025), “Selenite”, in Webmineral Mineralogy Database.
• “selenite”, in Mindat.org‎^[1], Hudson Institute of Mineralogy, 2000–2025.

• enlistee, tee lines

From Latin selēnītēs, from Ancient Greek σεληνῑ́της (selēnī́tēs, “moonstone”), derived from σελήνη (selḗnē, “moon”).

• IPA^(key): /se.leˈni.te/
• Rhymes: -ite
• Hyphenation: se‧le‧nì‧te

selenite f (plural seleniti)

1. (mineralogy, obsolete) moonstone

   Synonym: pietra di luna

2. (mineralogy) selenite