An opal and diamond cluster ringA lovely cluster ring containing an oval opal centre stone. The opal measures 11x7. 5mm, and is dark in colour with a large play of colour, ranging from peacock blue, luminous green and flashes of fireglow orange. The opal will be classed as a doublet, hence the slightly lower price. A doublet is a slice of opal placed atop a black ground, usually ironstone. Opal doublets are generally set onto strong Ironstone backing which is a brown black in