which is heavier granite or pumice
There are lots of different metals and lots of different stones. Aluminium, for example is less dense (lighter) than granite Iron is more dense than pumice (a volcanic rock that actually floats on water). Even rocks such as granite vary in density. To answer your specific example, as granite contains heavy metals it would normally be denser than iron. Obsidian is likely to be less dense than iron as it contains lighter elements. Generally the metals are heavier than stones.But not in all cases.