prove yourselves

"Hello, kids! I will be your guide for the next portion of this adventure," said the Burning Man. "But first, you must identify three objects."
The heroine picked up the first, a heavy piece of twisted stone.
"I have no idea," she said.
"It is a whale's ear bone," said the hero.
"That is correct," said Burning Man. "Next?"
The hero hefted a glossy black rock, scalloped with channels. "This is a piece of obsidian used to make knives."
"Correct,' said the Flaming Man. "And?"
"A pot," said the heroine.
"A fake," said the hero.
"The hero is right again," said Burning Man.
"Well," said the heroine. "He DID grow up on an archeological dig in Alaska."