The scientific investigation of works of art has an essential role in understanding museum collections and is fundamental in establishing successful conservation and restoration strategies. In the multidisciplinary environment of museums, scientists work with conservators and curators not only to more profoundly understand works of art but to better preserve them, and this often involves using analytical techniques borrowed from different disciplines of Earth sciences (e.g. mineralogy, geochemistry, and petrology). Two case studies – the stones of Angkor (Cambodia) and a blue paint mineral pigment – demonstrate how the Earth sciences are helping to identify, determine provenance, and conserve a broad spectrum of works of art. The impact on archaeological and art historical scholarship is substantial.