What does gadolinite mean?
Gadolinite is a rare silicate mineral composed of beryllium, iron, and the rare-earth element yttrium, together with smaller amounts of other rare earths. It typically forms black, brownish, or greenish-black prismatic crystals with a vitreous lustre and occurs mainly in granite pegmatites, notably at Ytterby in Sweden, the famous quarry that yielded several rare-earth elements. Named in honour of the Finnish chemist Johan Gadolin, who first analysed it, the mineral holds an honoured place in the history of science: yttrium, terbium, erbium, and ytterbium were all originally separated from its ores, and the synthetic-chemistry staple gadolinium shares its patron. Today gadolinite interests primarily mineralogists, collectors, and historians of chemistry rather than industry, having been superseded by richer sources of rare earths. In usage it is a specialist noun, encountered in geological literature, museum labels, and technical descriptions of pegmatite deposits.
nounA rare dark-coloured rock-forming mineral, a silicate of beryllium, iron, and the rare-earth element yttrium, occurring chiefly in granite pegmatites.
- A rare black to greenish-black silicate mineral of beryllium, iron, and yttrium, typically found in granite pegmatites and valued historically as an early source of rare-earth elements.
"The museum's mineral collection featured a striking specimen of gadolinite from a Norwegian pegmatite."
"Chemists in the nineteenth century painstakingly extracted new rare-earth elements from crystals of gadolinite."
"The collector prized his gadolinite specimen for its glassy black lustre and its place in the history of chemistry."
Rarely used; gadolinite is normally treated as an uncountable mass noun, but a plural may appear when referring to distinct specimens or occurrences.
"Several gadolinites from different localities were compared in the study."
This single black mineral made scientific history: the rare-earth elements yttrium, terbium, erbium, and ytterbium were all first isolated from it, and both it and the element gadolinium honour Finnish chemist Johan Gadolin.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of gadolinite
Gadolinite takes its name from the Finnish chemist Johan Gadolin (1760–1852), who carried out the first chemical analysis of the mineral in the late eighteenth century at the suggestion of Johan Gottlieb Gahn. The mineral had earlier been known as ytterbite, after its discovery locality near Ytterby in Sweden. The rare-earth element gadolinium, isolated later from related minerals, was likewise named in Gadolin's honour, making the chemist one of the few people commemorated by both a mineral and an element.
How gadolinite is actually used
Gadolinite is used almost exclusively in mineralogy, geology, and the history of chemistry; it appears rarely in everyday language. It is treated as an uncountable mass noun when referring to the mineral in general, though a countable plural exists for individual specimens or occurrences.
Easily confused with gadolinite
Gadolinite is a rare silicate mineral, whereas gadolinium is a chemical element (a metallic rare-earth metal) whose name honours the same person, Johan Gadolin.