Zircon and diamond ring, mid 20^th century. Zircons are natural stones, not to be confused with the modern man-made diamond simulant cubic zirconia. Zircons have been prized throughout history for their brilliant lustre and their array of bright, vivid colours, demonstrated by the beautiful stone at the centre of this ring. This striking bright blue colour is among the most popular for zircon, shown off here by the emerald cut – an unusual choice for zircon. Flanked by two brilliant-cut diamonds, this would make an unusual and extremely attractive choice for an engagement ring, or as a statement cocktail ring for special occasions.