What Is Ambergris?

You may have heard the story about eight-year-old Charlie Naysmith from Dorset, UK, who was walking along the beach with his dad and found what looked to be a very odd rock. He and his dad used Google to help identify it as ambergris. Weighing more than a pound, it is said to be worth up to U.S. $63,000.

Ambergris is a solid, waxy, flammable substance of a dull gray or blackish color produced in the digestive system of and regurgitated or secreted by sperm whales. But why does it have such a high value?