aeschynite
/ˈɛskɪnʌɪt/(also eschynite) Mineralogy
noun
A dark brown rock-forming mineral containing cerium, titanium, and niobium; now also more fully aeschynite-(Ce). Also: either of two related minerals, in which cerium and calcium are replaced either by yttrium, erbium, and calcium (more fully aeschynite-(Y)), or else by neodymium and cerium (more fully aeschynite-(Nd)).
- Aeschynite is an oxide and hydroxide of several elements with the basic formula AB2(O,OH)6, where A is one or more rare earth elements, calcium, ferrous iron, and thallium, and B is titanium and niobium. An older name for aeschynite-(Y) is priorite. Crystal system: orthorhombic, but the mineral is usually metamict in its natural state..
Origin
Mid 19th century; earliest use found in Edinburgh Journal Science. From German Aeschynit from Swedish äschynit from ancient Greek αἰσχύνη shame, dishonour, disgrace + Swedish -it. The mineral is so named in allusion to the inability of chemical science, at the time of the discovery of the mineral, to isolate some of its constituents.