The nine turquoise mosaics from Mexico are among the most striking objects in the collections of the British Museum. They include masks, a shield, a knife and a helmet, all originating from the Mixtec and Aztec civilisations first encountered by Europeans during the Spanish conquest in the early sixteenth century. Recent scientific investigation undertaken at the British Museum has dramatically developed our knowledge of the objects by characterising, for the first time, the variety of natural materials that were used to create them. Other scientific insights allow us to appreciate the exceptional skills employed by their makers. The role of turquoise mosaics in ritual is explored by drawing on contemporary accounts and early pictorial books or codices which place the objects in their historical context. This highly illustrated book interweaves diverse perspectives to offer a succinct and informative overview of these beautiful and mysterious objects.