World Error Identification -Security Edge Task with Prize!

[Australian coin]

Rhodesia 10 cent?

[markn]

Ours weights 5.65g on the nose.

[Australian coin]

bahaha just found the eBay listing :heart:

[markn]

bahaha just found the eBay listing :heart:

There's a story behind the listing.  We saw the error a while back and watched, it ended without selling at an opening bid of $200.  So we offered a little less (not much but a little) and the seller refused.  So we offered the $200 and the seller went on to tell us that he'd been told the coin was worth a lot and he'd be sending it to the UK where a dealer had assured him he'd get $1000 for it so we should offer more. We refused.  And a few weeks later he listed it again for $200 and we won it at the opening bid.  Strange.

[Australian coin]

here's you answer probably cant research it any further cos its truly a one off >> well it doesn't exist online :heart: do I win xx
http://minterrornews.com/discoveries-5-4-04-on_the_edge.html

[markn]

here's you answer probably cant research it any further cos its truly a one off >> well it doesn't exist online :heart: do I win xx
http://minterrornews.com/discoveries-5-4-04-on_the_edge.html

We've read that article and no-doubt the same sort of mix up happened with our coin.  Sadly his conclusion that the coin was struck on a Hong Kong 50c is wrong because a Hong Kong 50c weighs 5.83g and his error coin weights 5.0g.  Just goes to show you can't believe everything you read on the Internet.

[Robster]

Followed this with interest- particularly the "Security Edge". I would assume that very few coins with this edge would me minted in 'primo' condition and would be almost impossible to find undamaged in circulated coins.!
That said, I do find the edge adds to the coins allure.! Thanks for sharing.!!:ok:

[Jaseee]

What about its diameter and thickness?

[Australian coin]

ok, I asked the question, how are the coins actually made, turns out that the security edge is the final part of the coining process, so the coin could have been stamped normally then put thru a Hong Kong security rimmer:

copy>>
Normally high value coins are produced with a 'Security edge'. This is done to check counterfeiting of coins. Coins having 'security edge' are first struck with the usual upright milling, at the time the obverse and reverse designs are impressed upon them. These are next passed through a second press, where the security mark is put on the edge, under pressure.

But, while being fed into the second machine, if a few coins accidentally skip the press, these may go to circulation with normal upright milling. Thus we find another type of error in coin specimens with upright milling which should have a 'security edge'.
http://beekar-the-numismatist.blogspot.com.au/p/mint-error-coins-of-india.html

[enworb]

Closest I have been able to find so far is the British Borneo and Malaya 20 cent. Mass is spot on but some sites show milled edge whilst other show security edge.

[markn]

Closest I have been able to find so far is the British Borneo and Malaya 20 cent. Mass is spot on but some sites show milled edge whilst other show security edge.

I've found the same information.  The Malayan 20c is the current leading contender but until I can see an edge it's not certain.  Trying to find a contender is fun

[markn]

ok, I asked the question, how are the coins actually made, turns out that the security edge is the final part of the coining process, so the coin could have been stamped normally then put thru a Hong Kong security rimmer:

Security edges are applied before or after the minting process.  There's no hard and fast rule.  In the case of this coin I suspect it was done before the minting process because of the wire rim around the coin.  If it was rimmed before striking there would be a slight bulge right around the rim prior to striking.  The extra metal in this area would result in a localised area of high striking pressure and some of the metal would squeeze in between the collar and the obverse/reverse dies.  Hence the wire rim.  Wire times are also a typical indicator of high striking pressure (on proofs for example).

[enworb]

I looked through my world coins and have a 1948 Malaya 20c. It has a reeded edge. The design may have changed between 1948 and 1961 though.

[Mister T]

Malayan 20c pieces on ebay (as opposed to the subsequent British Borneo and Malayan 20c piece) have reeded edges: http://www.ebay.com/itm/Malaya-1948-toned-20-cents-/380582173164?pt=US_World_Coins&hash=item589c7719ec and http://www.ebay.com/itm/Excellent-Malaya-British-copper-nickel-20-Cents-1950-Coin-Look-bid-buy-it-now-/140917782573?pt=US_World_Coins&hash=item20cf5ab82d

edit: see what enworb said.

[Australian coin]

Hmm, the coin is still strange don’t know why it has interrupted milling?

So I thought about maybe a "Experimental Coin” but usually they have “exp” on it or two lines thru the picture front and back.

History of Zambia coinage
date
era
1953 - 1964    Federation of Rhodesia and Nyasaland
... - ...    Northern Rhodesia
1964 - ...    Republic of Zambia


Republic of Zambia
http://numismaticon.com/catalog/Zambia/coins/page_1#era_2025

So the one shilling design was only for 1964, they didn’t date them other years, so the coin that you have could be an experimental coin, before actually minting the coins.

Haven’t searched other sites to make sure that they did that design for other years, pretty hard coin to research in general anyway