Most of the time you can look at the rim...if you see a copper looking middle...then that is the copper...better known as a Clad coin....but sometimes you have to get the weight....can you post a photo?..maybe we can help Speedy
to CoinTalk. I think you're referring to 100% nickle coins, such as Japanese Y#75, a ¥50 minted from 1955-58 and 100% copper-nickle alloy coins, such as the US 5¢ nickle, not the post-1964 US dimes and quarters. Nickle is magnetic, it's alloy with copper isn't; so if your silvery-grey coin has a consistently colored edge with no copper strip in the middle doesn't ring like silver when tapped is too heavy to be aluminum, and sticks to a magnet it's nickle. Otherwise it's cu-ni.
There are a lot of copper nickel coins in the world. Most of these range from about 25% nickel to about 88%. Nickel has to be nearly pure (99%+) to be magnetic but varies with the alloy. As a rule higher percentages of nickel mean less darkening in circulation but because of various other metals often added in small quantities it can be very tough to tell. Canada, New Caledonia, Japan, and Lebannon are the only countries which spring to mind that have pure nickel coinage. Generally figure 25% but clad is lower because of the copper core.
thanks what i mean 4 files of king ghazi (iraqi king) 1938 it is 2 issue in the same date but differ in metal one in nickel and second is co-ni
KM#105a, the copper-nickle version is listed in Krause as weighing 21g, even though it has the same diameter of 21mm as KM#105, the nickle version, which is ridiculous since the cu-ni 10 fils is listed as the same weight in both metals. Chalk up one more victory for the Krause printing gremlins. At any rate, there are two ways to tell the difference. The hard (and expensive) way is to submit the coin to a metallurgy lab for destructive testing which will reveal the exact alloy. The easy (and cheap) way is to take a magnet off your refrigerator, place the coin on a table, and put the magnet on top. If the coin stays on the table when you lift the magnet, it's cu-ni. If it comes up with the magnet, it's nickle. TaDa! :hail:
