Can someone enlighten me on this copper/bronze version of my silver 10 Kreuzer. Thx, Joe Austria - 10 Kreuzer - 1872 - KM #2206 - 1.6667g - 0.4000Ag - 0.0214oz Austria - 10 Kreuzer - 1872 - Cu or Bronze Carn't find it in the Krause catalogue
They're the same coin, both KM#2206. Low grade silver often looks like copper after wear and/or environmental exposure.
DCH is correct I think Yes, your two coins appear to be the same type of silver coin. I assume that they are the same size & weight. Of course it could always be a wrong metal error but that would be quite rare I think. The obverse of this 1891 Portugal 200 Reis looks like a copper coin. The reverse shows that the coin is actually silver.
That's what I thought at first, but here's a close up of the coin. The scratches are deep and yet the color is way to brown to be mere toning. At least that's what I was thinking. I figured someone skilled on Austrian coinage might make out whether it may be an off metal strike or a pattern or play money by the Ch. Lauer.
Play money would generally not be of the exact size as the real coin and also would not have all the same legends. Can you post the weight? If it's just slightly lower than it should be, then this may be a case of improper alloy mixing. Could just have been struck on a planchet that has a lot more copper in it than they normally should. I first was thinking old counterfeit, but the details are too good for that.
That is much too low. Even considering the condition I don't think the wear can account for over a 0.4 gram weight difference on a coin this small. Now I'm thinking it's a very sharp counterfeit, which actually makes it more interesting (to me at least). =)
I wasn't referring to normal toning. This coin is not silver as the term us usually used in numismatics...It's Billon. In this case 60% of the coin is copper, so it takes very few silver atoms oxidizing before the visible color shifts. Some billon coins were actually treated with acid to remove the surface layer of copper, giving the coin the appearance of good silver until the surface layer is worn off. But...if the weight is really 1.2g the whole billon thing doesn't matter. Typically to lose 20% of its weight a coin would worn smooth. Assuming it has the same physical dimensions as a coin of 1.667g, then I calculate the specific gravity at 6.8(I'm heavily medicated with the Flu so my math may be way off)...basically pure zinc. Depending on how much material has worn off it could stretch into the range of bronze, or some high antimony/copper alloy. What does your silver coin weigh? I wonder just how tight the mint standards were that year.....
Corroded Billon It has the appearance of having been in the ground. Like an acid soak, the coin would disintegrate possibly accounting for the light weight. Then again, it might be a valuable off metal error.
I calibrated my scale. It was off. new weight 1.4g I think you may be on to something Numismat. It might be a counterfeit. It could have had a silver wash. But then again, it could be an off metal strike. Here's the details so far: 1) The deep scratches may be from someone purposely scratching it to reveal it's true content. 2) The scratches are deep and run in one direction. 3) They don't look like they were made by normal circulating use. 4) The low relief areas do not have much detail. 5) The low relief ares are deep and very toned, almost blackened like British bronze Farthings. 6) Both coins are the same date and denomination. Why would one be made in billion and the other in 40% silver? 7) The denomination is rather a low value and wouldn't be worth the effort for a counterfeiter, I suppose. 8) Both coins are 17mm and the 40% silver is 1.6g and the bronze toned coin is 1.4g 9) The bronze toned coin has a die crack mark between the "I" and the "D" at the back of the head on the obverse side. 10) Mintage: 70,000,000 It was the last 10 Kreuzer made before the reform coinage took effect in 1892. 11) Almost twenty years had past between the last 10 Kreuzer and the reform coinage. The bronzed toned coin could have been made with old worn dies and with a debased silver content to match the changing economic times just before the currency had been reformed. What do you guys think? Be brutal. The truth is not always nice, but necessary. Am I on a wild goose chase here?
It may well be a case of official dies falling into the wrong hands. This is known to have happened at a couple of the Mexican mints in the 1830's. The coins had a genuine stamp, but were very much debased and also underweight. The blackened tone to the low lying areas you mention can be leftovers from a wash or plating.
Interesting... In that case can you take a look at another post of mine referring to Mexican coins: http://www.cointalk.com/t195958/ Thx, Joe
I have 20 kreuzer coin (1868, km#2212) with exactly same "problem". Here are the pics - silver one 1870 and "copper" one 1868.
