There are a number of books about history, one of which is titled, "The gem of the dragon."
You sit down and read the story.
Learning of the evil, Duncan broke into that cursed place and yanked the gem from the dragon's mouth. We gaped in horror as the glow of the gem brightened in his hand. Duncan did not waver even though we could smell the stench of his burning flesh. He carried it out to the road, each step an agony, until he reached a vase. The searing gem stuck to his flesh as if it did not want to slide into that prison. With a cry to break the hardest soul, Duncan pushed the gem into the vase, taking strips of skin with it. He turned to us, looked down at his hands, then collapsed.
We have never forgotten that long day and we pray that nobody ever rediscovers the evil possible with the power of the gem.