noun🔗ShareБиотитA dark brown mica; it is a mixed aluminosilicate and fluoride of potassium, magnesium and iron."The shiny black flecks in the granite countertop are likely grains of biotite, a type of mica. "Блестящие черные пятна в гранитной столешнице, вероятно, зерна биотита, разновидности слюды.geologymineralsubstancematerialchemistryChat with AIVocabulary GamePractice Reading
