The Four-Year-Old, decisively: “Gold.”
Mother, a bit chagrined at how expensive her daughter’s tastes are already getting: “Why?”
The Four-Year-Old: “Because it’s rare and it was cooked in a star that died long ago.”
Mother surreptitiously Asks the iPhone and finds Cosmic Crashes Forging Gold (Max-Planck-Gesellschaft).
Mother: “Huh. Well, I suppose that’s ok.”
(Not that The Four-Year-Old read that article, you understand. She learned about the cosmic origin of gold on an episode of Into the Universe with Stephen Hawking.)