HE'LIOTROPE, noun [Gr. the sun, and to turn.]
1. Among the ancients, an instrument or machine for showing when the sun arrived at the tropics and the equinoctial line.
2. A genus or plants, the turnsole.
3. A mineral, a subspecies of rhomboidal quartz, of a deep green color, peculiarly pleasant to the eye. It is usually variegated with blood red or yellowish dots, and is more or less translucent. Before the blowpipe, it loses its color. It is generally supposed to be chalcedony, colored by green earth or chlorite.