tranquillityite

== English == === Etymology === From tranquillity +‎ -ite, after the Sea of Tranquillity, a basin on the Moon where the mineral was first found. === Noun === tranquillityite (plural tranquillityites) (mineralogy) A hexagonal dark red mineral containing iron, oxygen, silicon, titanium, yttrium, and zirconium. ==== References ==== David Barthelmy (1997–2026), “Tranquillityite”, in Webmineral Mineralogy Database.