The objective of this short review and update is to present the state-of-the-art on the geology and
gemology of demantoid garnet deposits. The different studies conducted over the last thirty years
provide the opportunity to unravel the features of the gem andradite, a green variety of garnet through
field and laboratory research, including geology, petrography, gemology, fluid inclusions and stable
isotopes. The different features are compared in order to approach the question of the geological and
geographical origins of the rare demantoid garnet
