Australian-Coins Forum

Australian Coins, Banknotes and Exonumia => Australian Pre-Decimal Coins => Topic started by: ErikP on February 21, 2015, 04:25:29 PM

Title: 1973 2 cent Planchet
Post by: ErikP on February 21, 2015, 04:25:29 PM
[attachment=3154][attachment=3155][attachment=3156][attachment=3157][attachment=3158] Hi, inadvertent purchase recently in bulk lot. 1973 2 cent. weight 2.45g One of the photos show it sits into a normal 2 cent. Any answers for what is if not a minted coin or happened at mint. Thanks ErikP

ps coin its not rotated lines up each side
Title: RE: 1973 2 cent Planchet
Post by: trout on February 21, 2015, 04:43:39 PM
Looks like a "Bilge Coin" to me.
Alkaline environment "Dryer Coin" type effect due to the boats movement and the effect of electrolysis in the bilge water.
The effects of this environment is that the rim is constantly abraded and "Fresh metal" is available to be degraded the rest of the coin gets eaten away at an even rate, The porous look of this coin equates to either acid or alkaline damage .
PMD is MHO.  
I am an ex professional fisherman and have actually come across these from time to time :ok:
Title: RE: 1973 2 cent Planchet
Post by: ausjack on February 21, 2015, 04:49:29 PM
Very unusual! It looks like it might have spent a bit of time in water or something like that so might be what they call a dryer coin, or someone might have been in the shed and it's had a slight acid bath but will need someone that knows a bit more than me sorry.

doh, to quick off the draw trout and I type too slow :laugh2:
Title: RE: 1973 2 cent Planchet
Post by: ErikP on February 21, 2015, 04:58:51 PM
Hi Trout, thanks seems a reasonable answer.  digital microscope possibly shows the surface as eaten away. Just a couple more close up shots with rim and raised defined '2'. I guess my question why has the '2' such beaut definition if was being eaten away at a constant rate. regards ErikP

Hi Trout & Ausjack I contacted the person I bought the coinsd from, and the reply was no idea. But had kept the coins for about 30 years since younger days when collected a few coins and banknotes. Seller Couldn't remember this coin specifically but hadn't added to the collection for many years. Seller Lost interest as a teenager. Seller said was never a fisherman. Regards ErikP
Title: RE: 1973 2 cent Planchet
Post by: markn on February 21, 2015, 05:59:10 PM
Been in something acidic most likely.
Title: RE: 1973 2 cent Planchet
Post by: ErikP on February 21, 2015, 07:59:23 PM
markn, okay if all it could be fair enough, thanks EriKP
Title: RE: 1973 2 cent Planchet
Post by: markn on February 21, 2015, 08:12:10 PM
Sorry the obverse is a dead give away.  I've seen a lot of bronze coins that look the same.  It's not a "dryer coin" as suggested above, they have a quite different look.  Your coin has been sat obverse down in something acidic.
Title: RE: 1973 2 cent Planchet
Post by: ErikP on February 22, 2015, 01:24:28 PM
markn, I suppose valid reason. I wonder why then the coin is wafer thin compared to the normal 2 cent if it was eaten down that much why then didn't the whole of the obverse erode away? thanks ErikP
Title: RE: 1973 2 cent Planchet
Post by: markn on February 22, 2015, 01:50:40 PM
Quote from: 'ErikP' pid='67423' dateline='1424573668'markn, I suppose valid reason. I wonder why then the coin is wafer thin compared to the normal 2 cent if it was eaten down that much why then didn't the whole of the obverse erode away? thanks ErikP

Because when you put something in acid it eats everything away equally (well not exactly it does vary due to micro structure but it's close enough to make no difference).  So, the fields get eaten away at more or less the same rate as the high parts.  Hence there's design left.
Title: RE: 1973 2 cent Planchet
Post by: ErikP on February 23, 2015, 08:15:27 AM
Hi markn, thanks for explaining. I've put into a mylar pocket and put away, regards ErikP