what causes pennies to do this?

[Goes4ever]

looks like Lincoln has a disease

 

[RON (PA)]

I don't know. Looks like he got a bad case of warts from the wicked witch.

Could it be a chemical reaction of some kind with the environment.?? Just a guess.

 

[Goes4ever]

yeah he does look all warty lol

 

[garbageman]

Possibly coins that were found detecting, cleaned in a tumbler, then put back in circulation. Just my theory. HH- Garbageman

 

[Goes4ever]

hmmmm I have tumbled thousands of found pennies and they never bubbled up like that, they look more sand blasted when they are tumbled.

 

[garbageman]

Not damage from tumbling but the start of corrosion from being in the ground? I've had a lot of zinc cents that were in various stages of decomposing. HH- Garbageman

 

[dp2013]

I'm not an expert but it could be gas bubbles created at the mint. Google it and you'll find some information.
It's not really considered an error by most but they are a little out of the ordinary.

 

[Rorschach]

Yeah I noticed that also on pennies, I saw it a lot on the 1989 penny myself.

 

[Cerulean]

This is caused by galvanic corrosion between the copper and zinc layers. Happens when moisture gets between the zinc core and the copper plating, usually by seeping in through microscopic cracks in the copper plating. It's very common when two electrolytic metals are in close contact like this. This is why the plated zinc cent is a stupid coin design from an engineering standpoint.

Hey, US Mint... http://en.wikipedia.org/wiki/Galvanic_cell. Duh!

 

[trish76642]

I have 2 that are Black, slightly larger than a normal penny, and bowed in the center...i still havent found and explanation for that.

 

[ivan salis]

the real cause of the problem would be ---being made out of crappy zinc with a thin copper "over plating"-- these new "junk" cents just do not hold up well -- they rot almost upon impact with the ground it seems -- I often find half eaten looking "stinking zilincons" as I call em -- if in a area where indain head cents most like are not to be found (say after 1930)-- like say the adverage newish tot lot --I notch out the cent (zinc) icon on my ace 250 to cull these cruddy half eatten junk coins -- (if in a older possible "indain head cents " territory area don't this however since indain heads can tend to come in under the "cents" (zinc ) icon --- but in you in "indian free areas" like say the above said --tot lot do it -- you will find older copper type cents (pre 1983) will still ring up but under the dime icon --the copper core of a clad dime seems very similar to the machine --so under dime icon it goes --

 

[Felinepeachy]

LOL I call it penny pox.

 

[ivan salis]

peach cat yours is real copper cent (being a wheatie its 1958 or earlier ) -- so thats called "copper or bronze disease" -- thus its very differant than zinc rot cents made after 1983 *

 

[Felinepeachy]

Well I want to know why the heck they can't make a penny that lasts when a aluminum can buried in the ground for years comes out looking good as new? Maybe they should make pennies out of aluminum.

 

[XX]

Op's pennies have been heated.

Heat a couple of pennies and you will see the result.

The result varies based on temperature and rate of heating.

 

[ivan salis]

because zinc based copper plated cents are way cheaper to make than aluminum ones would be thats why peachy --

 

[Felinepeachy]

So Ivan, what you're telling me is that pulltabs are worth more than pennies? And here all this time I've been throwing them out. LOL

 

[ivan salis]

ah aluminum pulltabs compared to zinc cents -- sadly yes the pulltabs are worth nearly the same scrap metal content wize. --so how much is a pound of zinc (cents) worth vs how much a pound of aluminum (pulltabs) is worth ? currently ----zinc is .6713 per pound - vs aluminum at .6489- so on a pound for pound basis zinc cents are worth 2.. 24 cents a pound more than pulltabs --- sad huh? ---- I think of zinc cents as the "pull tab" of the coin money world

at least with "damaged pulltabs" you can turn em in at as scrap aluminum and get something for em -- but those dang messed up zinc cents are only fit for feeding into coinstar machines at a 9 % cash in discount (some are so bad even the stupid "coin counter" machine will not take em) -- ---since clearly no seeing human being will take those hidious things -- I feed the nasty critters to the stupid green "machine" at the 9% discount rate .

 

[Felinepeachy]

LOL Ivan, you are so funny.

 

[dp2013]

Ivan,
Consider getting a e-certificate at the coinstar machine instead of cash and you don't have to pay the 9% premium. They have many to chose from including Lowe's.