I've read about people who had cooling problems and didn't like the way the aluminum would draw heat from their chip to their sink and so they lapped a copper penny and put it between the sink and the chip. I thought of doing that but wondered if something a small as a penny was big enough to be of much help. I went digging for some coins I got during my spring break in 1989 when I went to Paris. I dug this coin out and thought of lapping it but the colour seemed a bit too yellow and not orange enough to be copper. I sanded the side not shown just a bit to see if it was just tarnish but it came out still too yellow for me to accept it as copper. My question is: Does anyone know if this coin is copper or brass or something else? It is a 10 French Franc coin minted in 1980. The other side has "REPUBLIQUE FRANCAISE" written on it and the edge side has "EGALITE FRATERNITE LIBERTE" on it. The coin is 25mm diameter and 2.5mm thick. Anybody have a clue to it's makeup? If it is brass how good of a conductor would it be?