Kris Lane is professor of history at the College of William and Mary. His previous books include Pillaging the Empire: Piracy in the Americas, 1500-1750 and Quito 1599: City & Colony in Transition.

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 colour 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 labour 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.