moonstone
nounUS /ˈmunˌstoʊn/
Etymology From moon + stone.
1
Chemistry, Geography, Geology, Mineralogy, Natural sciences, Physical sciences A translucent gemstone, an orthoclase feldspar, that has a pearly lustre.
- To give light to the presence chamber were seven escarbuncles, great as pumpkins, hung in order down the length of it, and nine fair moonstones standing in order on silver pedestals between the pillars on the dais.1922, E[ric] R[ücker] Eddison, The Worm Ouroboros: A Romance, London: Jonathan Cape […], →OCLC, page 3: