An Australian George V 1921 proof shilling is to lead a numismatic sale at Dix Noonan Webb in London on February 11 with a £100,000-120,000 ($150,940-181,128) estimate.

The lot is one of only six proof specimens and has only recently been unearthed.  

The 1921 George V proof features a star above the date

Following the first world war the value of precious metals increased substantially. It was decided to reduce the silver content of British coins, including those of the commonwealth.

To differentiate between the new lower silver content coins and their predecessors, the new issue was to be marked with a star.

The silver content was never reduced in Australia, but the 1921 issue was still produced using the star marked dies. A total of 522,000 were released into circulation, alongside the six proofs - which remain key Antipodean rarities.  

Also on offer is a British 1910 George V pattern crown valued at £80,000-100,000 ($120,752-150,940).

Christopher Webb, head of the coins department at Dix Noonan Webb, commented: "These are very exciting coins to include in our auction.

"The Australian 1921 Proof Shilling has lain un-noticed in a private collection for decades and we cannot trace any example of this coin having been offered for sale within the last 30 years. The George V Pattern Crown is excessively rare and comes with a distinguished provenance."

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