Are you a private individual, therapist? Select how many onyx pebbles you needOnyx pebble descriptionOnyx, also known as black agate, is a stone mined from volcanic deposits. This stone is made of silicon dioxide. It is deep black in color, and pearly with slight white reflections. This particularly solid stone has been known since ancient times by the Greek, Egyptian and Roman peoples, for the manufacture of decorative objects and dishes. The name Onyx given to this black agate comes from Greek and means nails. This refers to the legend that Venus saw her nails turn into black agate while her son, Cupid, tried to cut them off in his sleep. In India and Persia, onyx stones were used to limit pain during childbirth, and to keep the evil eye at bay. During the reign of Henry IV, Onyx appeared on the jewelry of the favorite of the King of Fr.