View Transcript
Episode Description
What is the world's oldest slice of mantle, and how did it reach the surface?
Today, we'll meet the first tangible piece of the world below the crust, a world humans still have not visited. Along the way, we'll meet an old mineral friend from Season 1, a researcher named Friend, and learn how diamonds can be a geologist's best friend when looking for slices of the mantle.
Extra Credit: Clean your bathtub, or call an old friend.