Although it should be used as a last resort test method, you could, uh, lick it. You don't have to all-out French it, just quickly jab the tip of your.
Most people who have spent a fair amount of learning about paleontology know about "the lick test", but I still can't find a real explanation to.
He said we too could go fossil hunting and told us about the lick test. He held up specimens found by tourists just like us. He reminded us.