George V Penny, No Reverse Image

Three possibilities occur to me.

It could be a mint error, with one side 'muffled' somehow - say by something getting in between the die and the coin. Very odd for a "real mint error" to produce one side looking normal and one side perfectly flat, but without seeing a pic it's still a remote possibility, I guess.

It could be a "lamination flaw" - where a coin effectively splits clean in half, due to a gas bubble or some such defect within the metal. Such a coin would look normal on one side, but should look "raw" with a laminar "grain" pattern on the other; it shouldn't form a perfectly flat surface. It's kind of a mint error, but because it's relatively easy to "create" a split planchet artificially, it may not be worth very much.

Third, and most likely possibility, is that it's simply been sanded down by someone. Prisoners, soldiers and anyone else with idle hands and lots of spare time commonly defaced coins like this to make a souvenir for themselves or their loved ones; the blank side would then be engraved with their initials or some such.

At 1" it would be closer to a British half penny in size. Is George V wearing a crown or is he bare headed. Commonwealth countries such as Canada and Australia also use the reigning monarchs effigy on the obverse of their coinage, but used a crowned king on it's coins. How worn is the obverse? I have some British George V penny and half penny coins that have been worn smooth from natural wear. Any chance of a photo?

OK, mystery solved. It is a British Penny however it has been defaced. I took it to a coin shop in town and they said it looked like a jeweler had shaved off the back as the ridge was missing. Oh well, it was fun searching it out. Thanks for everyone's input. I'm sure I will have more questions as I still have a ton of coins to go through.

Thanks again!

I have found coins similar to this whilst metal detecting. They are silver & they have been worn down on both sides & the coin warped. I have been told this was done on purpose & that they are called 'love tokens'. How correct this is I don't know.