Secrets in History

You walk around, admiring the architect of the run down temple. It's marvelous. And as you reach the center, you spot a strange stone. As you get closer to look at it, you can see it's some kind of mineral, simular to amethyst. Since you're not a geologist, you can't say what it is for certain. You decide for now to pick up the stone to weigh it, thinking that might help you figure out what it was most likely used for in the temple. But as you pick it up, you have white glowings marks on you.