Gaston Giuliani, Lee Groat and Federico Pezzotta (contact: giuliani@crpg.cnrs-nancy.fr)

Gems are minerals which are valued for their beauty and rarity. The purpose of this session is to gather the latest results related to aesthetic mineralogy, from descriptions of new occurrences of coloured gem minerals to the state-of-the art of advances in the scientific knowledge of their formation, their geologic and/or geographic origin, and to establish their mineralogical identities, in order to answer the unknowns of the question "why do minerals sometimes become gems?". The session will encompass all aspects related to coloured gem studies from field to laboratories including geology and genesis of the deposits, crystallography, gemmology, geochemistry, and experiments for natural and synthetic gems. Contributions will bring together academics, industry, mineral collectors and museum curators alike working to discover the secrets of the birth of these beautiful mineral specimens.

The keynote speaker will be Dan Marshall (Simon Fraser University, Burnaby BC, Canada)