Last week, a British man walking his dog on a beach in northern England came upon what looked like a waxy and smelly soccer ball-sized rock. Turns out, it wasn't an ordinary rock, it was something called ambergris, or Sperm whale excrement, and it's worth more than $100,000.
We'll talk to Christopher Kemp, the author of the book, "Floating Gold: A Natural and Unnatural History of Ambergris."