Odds and quads

The faces are rich in Jacobite decorative motifs. The entwined monogram incorporates the initials J.R. for "Jacobus Rex". A heart pierced with arrows symbolises the suffering of the exiled king, and a crowned thistle represents the unbroken line of monarchs ruling Scotland.

More enigmatic is a sheaf of corn with feeding birds. This may represent the ripeness of the Jacobite cause, but could have an added secret meaning, since the Latin for "ripe corn" - matura arista - is an anagram of "Maria Stuarta", or Mary Queen of Scots.

The egg, which is held by the University of Aberdeen, has inspired an Aberdeen graduate working in the catering industry to create a white chocolate version. The original is on display at the Scottish Parliament until 8 January 2011 as part of the exhibition Rebels with a Cause: The Jacobites and the Global Imagination.