[L,. achates; so called from the name of the river Achates in Sicily, where it was first found.] A variety of quartz, found in loose rounded pieces in rocks, or as loose pebbles in beds of rivers or gravel. Wood may be converted into agate by infiltration with waters carrying silica in solution, as in the celebrated petrified forest of Arizona. Agates show various tints in the same specimen, and the colors are delicately arranged in stripes or bands, or blended in clouds. They* take a fine polish, and are much used in the manufacture of rings, seals, beads, handles of knives and forks, cups, smelling bottles, and many other ornamental articles. Burnishers for polishing, used by bookbinders, are made of agate.