Among the magnificent gems and jewels left behind by the great Islamic empires, emeralds stand out for their size and prominence. For the Mughals, Ottomans, and Safavids green was—as it remains for all Muslims—the color of Paradise, reserved for the Prophet Muhammad and his descendants. Tapping a wide range of sources, Kris Lane traces the complex web of global trading networks that funneled emeralds from backland South America to populous Asian capitals between the sixteenth and the eighteenth centuries. Lane reveals the bloody conquest wars and forced labor regimes that accompanied their production. It is a story of trade, but also of transformations—how members of profoundly different societies at opposite ends of the globe assigned value to a few thousand pounds of imperfectly shiny green rocks.