Any tips for differentiating

mumu

Copper from bronze? Any toning differences or something along those lines to tell, namely in pictures?

PerryHall

<< <i>Copper from bronze? Any toning differences or something along those lines to tell, namely in pictures? >>



Bronze is just copper with a small percentage of tin added as an alloy to harden the copper which is a fairly soft metal. In theory the tin should give the yellow copper a slightly lighter color but I can't see it myself. Scientific tests can of course differentiate between the two.

notwilight

All lincoln copper cents and indians after 1864 are actually bronze. (5% alloying metals). So what are you trying to ask? --Jerry

mumu

<< <i>All lincoln copper cents and indians after 1864 are actually bronze. (5% alloying metals). So what are you trying to ask? --Jerry >>



I guess the question falls apart when applied to american coinage, but it was just a general question in metals. Say a trial pattern piece is struck in bronze for example and also struck in what is labeled copper, could you tell by looking.

IrishMikey

Some of the bronze patterns (where they also made copper) will have streaks where the alloy
was imperfectly blended. Other than that, it is often just an educated guess, unless a surface
analysis is performed.

BillyKingsley

You know, I've been somewhat embarrassed that I couldn't tell the difference. Reading this thread makes me feel better.

At least by now I can tell without looking if a cent is one made of zinc or not. Took me a while to be able to tell by feel.

PerryHall

<< <i>You know, I've been somewhat embarrassed that I couldn't tell the difference. Reading this thread makes me feel better.

At least by now I can tell without looking if a cent is one made of zinc or not. Took me a while to be able to tell by feel. >>



The easiest way is by sound---drop them on a hard surface and the copper cents sounds different than the zinc cents.

mumu

OK well then it is safe to say that by picture it is near imposible for the most part. This is actually a dark side question and I had to camoflaoge it be generalizing a bit for the selfish reason that this board is the more active one, and in the case of patterns it would still be applicable. To be more direct there is a coin that is listed in Krause as having been made in copper and bronze. The bronze being a regular issue and the copper an essai. They come up on ebay and are sometimes listed improperly. I *think* i have 2 versions of the copper pieces and would like to tell if one currently listed as the bronze versions is in fact the brozne as I wouldnt like to add the copper again *assuming thats what I have...but i really cant tell either way. I think there is mention of a mintmark placement to tell them apart, which would ocnfirm mine once I look...but still wouldnt help on the pictures because the mm is on the edge.

Here is a picture of the one in question. Is that verticle dark streak the melding mentioned?

ProofArtworkonCircs

<< All lincoln copper cents and indians after 1864 are actually bronze. (5% alloying metals). So what are you trying to ask? --Jerry >>

Bronze implies tin as part of the alloy. No tin after 1962, so those were brass cents.

Billyray

<< <i>Took me a while to be able to tell by feel. >>



I go by taste myself.

How Alloying Elements Affect the Properties of Copper Alloys

MORE ON THE DIFFERENCE BETWEEN COPPER, BRONZE AND BRASS

Hope those help

mumu

Any last minute help here? Auction ends today. I realize its probably impossible from pics.