These beautiful spherical stones take their name, "agate," from the Achatus river in Sicily where sizable deposits of the stone were discovered as early as 300BC. Banded agate (also known as onyx) is the stone most often used in carving cameos and intaglios, cutting them en cabochon or fashioning round beads with tp show off their stripes and swirls came into vogue in the mid 19th century.