Hardness of Solid Substances - Grinding Iron
Iron metal is not easily ground or crushed.
Iron metal is not easily ground or crushed.
Zinc metal is not easily ground or crushed.
Tin is a relatively soft metal that can be flattened.
Lead is a relatively soft metal that can be flattened.
Soap bubbles in a raft form grains of close-packed arrays with various orientations relative to each other.