Author Topic: This is not a halfpenny  (Read 587 times)

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Offline Figleaf

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This is not a halfpenny
« on: July 01, 2017, 07:17:32 PM »
I am looking for a bronze coin, for a British colony or ex-colony, struck at the UK Royal Mint, probably in 1965, possibly in 1964 with a diameter of 24.8 mm, a thickness of 0.95 mm and a weight of 3.1 grams.

While this coin was decorated with the dies for a halfpenny, the regular coins are 25.4 mm, 1.3 mm and 5.7 gram. BTW, that's not a die crack, but one of my last hairs.

It is not a fake, as it makes no sense to produce a perfectly good die for the wrong flan or to imitate an almost worthless coin, both economically and numismatically. It is not a plate rolled too thin because the flan is too small, so it must be a flan for another coin.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline Manzikert

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Re: This is not a halfpenny
« Reply #1 on: July 01, 2017, 10:21:03 PM »
I have seen a very similar effect which was produced by submerging a coin in acid, which removes metal uniformly from all surfaces, so not only is the coin thinner, but also smaller in diameter. Of course the details of the design are also very slightly fuzzy, as on your piece.

Alan

Offline Figleaf

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Re: This is not a halfpenny
« Reply #2 on: July 02, 2017, 10:06:18 AM »
I know this effect. It occurs in slow motion on coins buried in land treated with artificial fertiliser. However, it seems to work on silver only. It ruins copper coins and hardly affects gold.

More important, the die size on the coin hasn't changed: the pearl border is significantly closer to the edge of the coin than on the regular coins. If the coin had "shrunk", that distance would have been unchanged.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline FosseWay

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Re: This is not a halfpenny
« Reply #3 on: July 03, 2017, 11:56:06 AM »
Cyprus 5 mils? (Don't know the precise dimensions offhand but it is in the same ballpark as a halfpenny and was minted concurrently.)

Offline Figleaf

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Re: This is not a halfpenny
« Reply #4 on: July 03, 2017, 01:26:47 PM »
Thank you. Good try, but too heavy (5.6 grams) and large (25.4 mm). The Cyprus coin looks a lot like it was based on the regular halfpennies.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.