Chal-cēd’o-ny or Chāl’çe-do-ny, n.

(Synop., §130), n. [From Chalcedon, a town in Asia Minor, opposite to Byzantium.] (Min.) An uncrystallized, translucent variety of quartz, having usually a whitish color, and a luster nearly like wax.

☞ When chalcedony of different colors is arranged in stripes, or layers, it constitutes agate; and if the stripes are all horizontal, it is onyx. Chrysoprase is green chalcedony; carnelian, a flesh-red, and sard, a grayish-red variety. Dana.