Pendant with white opal and diamonds

Pendant with white opal of ca. 9 ct and brilliant-cut diamonds totalling ca. 0.15 ct, medium colour a. clarity, opal ca. 9 ct, with vivid green-red play of colour, 18K YG, 13.3 gr, L. ca. 4 cm, 1990s, minor signs of wear, incl. sales receipt from Australia (1994).