I obtained a coin that has a Mercury dime reverse on one side with ridges on the edge and a wheat cent reverse on the other side with smooth edges. No date could be obtained due to double reverse. The fime side shows minimal wear primarily on the staff and has a small indention under the word UNUM directly in line with the I in Dime. The wheat cent side displays a fair amount of wear, yet retains clear text. The coin is the thickness of a dime with the copper making up less than 1/2 the total thickness. The copper edges create a miniscule lip on less than 1/2 the circumference resulting in the coin fitting into any dime holder with no interference. Any idea what this could be worth, or how it ended up like this?