Nova Opal Gold Plated Adjustable Ring
The stone is Nova Opal(lab created synthetic opal), the stone measures about 12mm. The metal is gold plated brass. Please note that Nova opals show different colors as they move(see video).
The ring is adjustable, shown here at smallest size it adjusts to which is 7.5, with larger sizes the gap in the back of the ring expands to allow the ring band to become larger (see photos that shows the band and the back of the ring).