Sardonyx
A very beautiful and rare variety of onyx, composed of alternate layers of sard and white chalcedony, used by the ancients for cameo engravings. 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 very beautiful and rare variety of onyx, composed of alternate layers of sard and white chalcedony, used by the ancients for cameo engravings. See PRECIOUS STONES.