The story
From Biot + -ite, named by J.F.L. Hausmann in 1847 in honour of the French physicist Jean-Baptiste Biot, who, in 1816, researched the optical properties of mica, discovering many unique properties.
Etymology from Wiktionary, CC BY-SA 4.0.
biotite
Today it means: A dark brown mica; it is a mixed aluminosilicate and fluoride of potassium, magnesium and iron. Full definition →