Our sterling silver October birthstone hoop earrings display fiery opal gems set in simple polished surrounds dangling from three-quarter hoops. Each month of the year is associated with a different gemstone which brings luck to the wearer. The birthstone for October is opal. Beautiful, precious opals are unique gemstones, famous for their shimmering display of colours. Multi-chromatic flashes of colour appear and disappear as the stones move.