The 1855 proof half sovereign is one of the key rarities of the series with just 3 examples known, one of which is beyond reach in the British Museum. This example was re-designated as a proof strike as a business strike surfaced in 1979 with a subsequent example surfacing since then and another being identified in the Museum of Victoria. It is likely however that the issue was originally intended to be a pattern striking but the die was later used to strike business strikes. It was struck to proof quality with a deep cameo finish. One example sold as part of the Quartermaster sale in 2009 (Monetarium, 2009) .