This book traces the journeys of a stone across the world. From its remote point of origin in the city of Nishapur in eastern Iran, turquoise was traded through India, Central Asia, and the Near East, becoming an object of imperial exchange between the Safavid, Mughal, and Ottoman empires. Along this trail unfolds the story of turquoise--a phosphate of aluminum and copper formed by nature in rocks below the surface of the earth--and its discovery and export as a global commodity. In the material culture and imperial regalia of early modern Islamic tributary empires moving from the steppe to the sown, turquoise evolved into a sacred stone and color, a potent symbol of power projected in vivid color displays. From the empires of Islamic Eurasia, the turquoise trade reached Europe, where the stone was sought after and collected as an exotic object from the East. The Eurasian turquoise trade lasted into the nineteenth century, when the oldest mines in Iran collapsed and lost Aztec mines