Sparkling diamonds. Exquisite emeralds. Brilliant rubies. Shimmering pearls. For centuries, these precious gems have captured humankind, leading men and women to give up fortunes - even their lives - to possess them. Join National Geographic on a journey around the globe to discover the origins of these most coveted gems. You'll see astonishing amounts of earth mined to uncover rubies in Thailand or emeralds in Colombia. You'll meet a Tennessee... see more