selwynite

== English == === Etymology === From Selwyn +‎ -ite, after A. R. C. Selwyn. === Noun === selwynite (mineralogy) A tetragonal-ditetragonal dipyramidal deep purplish blue mineral containing aluminum, beryllium, hydrogen, oxygen, phosphorus, potassium, sodium, and zirconium. ==== References ==== David Barthelmy (1997–2026), “Selwynite”, in Webmineral Mineralogy Database.