Onyx
A chalcedony, with alternate layers of white, black, and brown. It is found in Saxony, Arabia, and Ireland, and is used largely for cameos. See PRECIOUS STONES.
Twelve hundred entries from the golden age of cast metal — how bells are founded, why brass is not bronze, what a cupola melts and a core withstands — by Simpson Bolland, the trade's great teacher.
A chalcedony, with alternate layers of white, black, and brown. It is found in Saxony, Arabia, and Ireland, and is used largely for cameos. See PRECIOUS STONES.