1970s diamond three stone signet ring in 9kt yellow gold

1970s diamond three stone signet ring in 9kt yellow gold. Set across the finger with three round brilliant cut diamonds in square collets, to a chunky three stone design with grain settings, incised details and polished borders, fitted to either side with broad integrated shoulders which taper to a solid shank. Estimated total diamond weight 0.65cts. Hallmarked 9kt gold, London, 1976.