What Is The Hardness Of A Mineral If It Scratches A Penny But Will Not Scratch Glass?
What Is The Hardness Of A Mineral If It Scratches A Penny But Will Not Scratch Glass? HARDNESS REPRESENTATIVE MINERAL 3 Copper penny 2.5 Fingernail Which mineral can scratch a penny but can not scratch glass? Also if a penny can scratch a mineral it rates a 3, a fingernail is 2.5, knife blade 5.5,