Two black opal rings; First consists of an oval Ethiopian opal cabochon, displaying play-of-colour in a digit pattern, against a treated dark background colour, collet set to mount with a plain flat shank, marked '925', opal measures 20.4 x 16.6 mm, ring size U; the other also has an oval Ethiopian opal cabochon, showing play-of-colour in polygonal patches, against a treated dark body colour, collet set to mount with a plain flat shank, marked '925', opal measures 17.7 x 12.6 mm, ring size R½; Total weight of items 13.0 grams (2).