Differentiating between Copper and Bronze

[brokencompass]

In the year 1906 British India coins started using bronze instead of copper for minting 1/12 anna, 1/2 pice, 1/4 Anna coins. I have two questions

1) Why Bronze? I know that Bronze is an alloy of Copper and Tin. Why was bronze preferred over Copper?
2) How can one visually distinguish between copper and bronze coins?

Thanks

[villa66]

1. Bronze is a tougher metal, and wears better and resists dings better than copper.

2. There is a difference in thickness where the 1906 coins are concerned, I think--but I'm sure someone who actually knows will be along in a moment.

v.

[translateltd]

2) How can one visually distinguish between copper and bronze coins?

Thanks

The easiest way is to spend many years looking at both :-)

Very difficult to put in so many words, but copper (especially in larger coins) often looks softer and has a more chocolaty colour.  Bronze looks harder and tends to blacken more with use, while copper keeps its brownish tone more.

All very vague, but that's my attempt to express what I perceive, anyway.

[villa66]

Any difference you've seen in mint-state copper v. bronze?

v.

[FosseWay]

Any difference you've seen in mint-state copper v. bronze?

v.

The only large quantities of mint-state copper I have are actually very modern -- namely copper-plated steel small change from the UK, Eurozone and other places. If you compare a post-1992 Unc UK 'copper' with an earlier one in the same condition, you'll notice that the copper one will have a more brashly pink sheen to it than the bronze, which is slightly more yellowish, IMO.

I'm presuming for these purposes that a pure copper coin and one that is made of something else and coated with pure copper look the same. I can't see any chemical reason why they shouldn't, but no doubt someone will enlighten me if there is a difference. 

For the kind of condition one generally encounters 19th-century 'coppers' in (that being the time when most coinages switched from copper to bronze; India and Italy were exceptionally late), personally I find it much more difficult. I just know from books when countries changed if I handle their coins often enough, and it's difficult to know whether I can tell the difference between pre- and post-1860 UK pennies because there's a definable difference in the feel or look of the metal, or whether it's just that the design changed at the same time.

[Harry]

So is there any difference between the design of the bronze and copper coins of British India King Edward VII? In otherwords, the design for the Edward 1/12 anna, 1/2 pice and 1/4 Anna coins did not change but the metal did, is that correct?

[brokencompass]

As far as I know, there are no differences between the design of the coins. They are exactly the same. So only the metal was changed in 1906.

[Coinsforever]

During transition period in 1906  from copper to bronze , eventhough design remained unchanged the weight of later  coins got reduced .

for example in case of 1/4 Anna of Edward

Actual Weight (g) Copper
6.42-6.56

Actual Weight (g) Bronze
4.76-4.99

Best example is 1906 1/4 Anna both in copper & bronze . I've coins of 1906 in both metals interestingly  thickness of bronze coins are less and therefore weight is less eventhough design are exactly matching.

AFAIK Neither SCWC nor baldwin or any other reference catalog (Not sure about pridmore -I've no pridmore) had indicated this point of variation of thickness in 1906 coins.

Cheers

[chrisild]

This will take us even further away from India and the early 20th century but Austria now issues some of its collector coins in copper. Here is an example. That is, the versions of the €5 and €10 pieces that can be had at face are no longer silver but pure copper - and I cannot tell the difference, color wise, between those and newly issued 1/2/5 cent (copper-plated steel) coins.

Christian

[villa66]

..you'll notice that the copper one will have a more brashly pink sheen to it than the bronze, which is slightly more yellowish, IMO....

My sense of color is unfortunately not so well developed that I would have thought to use "pink" or "pinkish," but I can see that now, now that the word is out there. Thanks.

v.

[brokencompass]

Here's a pinkish example of a copper 1889 1/4 anna and the reddest example of 1930 1/4 Anna

In hindsight, I can tell the difference between the two. The 1930 1/4 anna totally misses the Pinkish tinge

see here the 1889 coin and here the 1930 coin.