The Collaborative International Dictionary
Meionite
Meionite \Mei"o*nite\, n. [Gr. mei`wn smaller. So called in a allusion to the low pyramids of the crystals.] (Min.) A member of the scapolite group, occuring in glassy crystals on Monte Somma, near Naples.
Wiktionary
meionite
n. (context mineralogy English) A silicate mineral belonging to the scapolite group.
Wikipedia
Meionite
Meionite is a tectosilicate belonging to the scapolite group with the formula CaAlSiOCO. Some samples may also contain a sulfate group. It was first discovered in 1801 on Mt Somma, Vesuvius, Italy.