It's 25mm silver and has a crown on the top and ribbons on the side the rest of the coin is gone it's a pop out any help most appreciated
Looks like a smashed up Queen Victoria coin. At least based on the bit of crown I can see. Who knows?
I'm thinking Imperial Germany possibly a one mark coin. However, it can be probably be narrowed down to one of the monarchies in Europe or their colonial possessions before the beginning of the First World War.
I was about to say a pre-1937 Canadian quarter or dime, which also had crowns on top of their reverse design, but you would see part of the maple leaf wreath if that were the case. The style of the crown, and the ribbons there on either side of it, confirm the ID as being an Imperial German coin, as @Bradley Trotter suggested. But what is the diameter of the coin, and is it silver or copper-nickel? There were German minor denominations (5- and 10-pfennig, for example) which bore the same crowned eagle design. If it is around the size of a US quarter, and silver, then it is a 1-mark piece. If it is sized more like a US nickel, and more the color of a nickel, then it's a 10-pfennig piece. A 5-pfennig would also be the color of a nickel, due to its copper-nickel composition, but smaller still- more like a US dime in size. That mustachioed gentleman looks quite Germanic. It's a very neat piece. Quite unusual and special, I'd say.
Sounds about right, though the Numista catalog lists them at 24 mm: https://en.numista.com/catalogue/pieces7031.html https://en.numista.com/catalogue/pieces3412.html (The 10-pfennig would be copper-nickel and 21 mm.)
I notice that Numista lists the thickness for the (1873-1887) Type 1 at 1.4 mm and the (1891-1916) Type 2 at 1.44 mm, so if you had some really precise digital calipers, maybe you could narrow the date down that way. If I were to venture a wild guess, I would imagine this is probably on a Type 2 (KM 14) Mark, since these repoussé "popout" coins became popular around the turn of the century, though that of course doesn't mean an earlier (Type 1) host coin is out of the question.
Yes, I imagine the movement of the metal could account for the slight discrepancy in the diameter. Both the Type 1 and Type 2 Marks had reeded edges. Neat piece of exonumia, there.
It's safe to assume that we've got an 1873-1916 silver German 1-mark piece, at least, so that mystery is solved.
