gadolinite /ˈɡadələˌnīt, ˈɡædələˌnaɪt 
/ ▸ noun a rare dark brown or black mineral, consisting of a silicate of iron, beryllium, and rare earths.
– ORIGIN early 19th century : named after Johan Gadolin (1760–1852), the Finnish mineralogist who first identified it.
EnglishOxford New American Dictionary
