Portal:Minerals/Did you know/3


 * ... that the Lewisian gneiss (pictured), forms the basement to Torridonian and Cambro-Ordovician sedimentary rocks in the Hebridean Terrane?
 * ... that abernathyite is both fluorescent and radioactive and is named for the mine operator who discovered it?
 * ... that the minerals armalcolite, pyroxferroite and tranquillityite were discovered in lunar rocks?
 * ...that the streak of a mineral, the color of the mark it makes when rubbed on a plate, is usually a more consistent identifier than the color of the original mineral?