calamine (n.)

"zinc carbonate," also, confusedly, "zinc silicate," 1590s, from French calamine, from Old French calemine, chalemine (13c.), from Medieval Latin calamina, corrupted by alchemists from Latin cadmia "zinc ore," from Greek kadmeia (see cadmium). Or possibly the Medieval Latin word is from Latin calamus "reed," in reference to the mineral's stalactite form in furnace chimneys.