Onyx and Sardonyx
Onyx and Sardoynx are both types of Chalcedony. Both stones are banded which means they have parallel lines running through them. Onyx comes in black or white, while Sardonyx is usually dark brown, orange brown, or brownish red.Since the Ancient Greeks, Onyx and Sardonyx are extremely popular for cameo brooches, beads, and tablets.
Sources: Brazil, USA, Madagascar.
Hardness: 6.5-7 on Mohs scale.
Toughness: Good.
Sardonyx is an alternative birthstone for August.
To view our collection of Onyx and Sardonyx jewellery please visit our Capel Street store.