After the talk of these a while ago I decided to start weighing all the '83 cents I come across. Recently I found one that weighs 2.99 g. Reproduced on 3 different scales. I'm not familiar with the tolerances of copper cents- does anyone know what they might be? I have found zinc cents weighing the whole range between 2.35 and 2.65 grams and assume the copper range is similar. I've attached photos if anyone's curious; it's not dirty or glue-encrusted in any way so that can't make up for the extra mass. On a side note, what TPG has more of a reputation (i.e. authenticates more often) for strikes on "foreign planchets"?
if you have a metal detector, it will have a different reading and tone if it is copper. at least mine does. on mine it says 1 cent with a medium tone when i put a zinc cent in front of the search coil. when i put a copper cent, it gives the reding 10 cents and has a high tone.
That's certainly within the range of copper-alloy cents. You may have a transitional error worth several thousand dollars. Does it have the clear ring of a copper-alloy cent?
The noramal weight of a copper cent is 3.11 grams, so I don't know what to tell you. Nice find though. Good luck on it. Phoenix
To be honest, I have trouble audibly distinguishing between the two. Is there a way to produce the sound without potentially damaging it? Drop it on a wooden table or something?
For the amount of wear on that coin, 0.1 grams of loss is not that unthinkable. It's a shame it's in such condition if it really is copper.
Balancing the coin on a finger and tapping it with another cent does the trick. A low drop onto a formica kitchen countertop also works. A density (specific gravity) test is the gold standard, but few people have the requisite equipment.
Thanks- I knew that the mint targets 3.11 g but the question is more, how much variance do they allow? Which Mike said was at least 0.12 g since 2.99 g is within bronze planchet tolerance.
Few test results- tried 5 known bronze and 5 known zinc cents on the metal detector (Garrett GTA-500) and all 5 bronze were at "9"; the zincs were between "7" and "8"; the coin in question was an "8". Ring test- coin in question sounded more dull, like the zincs. Will try specific gravity hopefully later this week.
Well, you never know. Personally to me, it doesn't have that copper "look" if that makes any sense. But you never know. Good luck. Phoenix
If it is copper-plated zinc, then it's still a great error, since it would represent a cent struck on a planchet punched out of rolled-thick zinc strip. Those are really rare.
