Abstract: Fluids play a key role in the origin of rocks and ore deposits. They are the connecting media for the interaction between different Earth layers. Currently in fluid research, most geologists mainly study fluid alteration of existing minerals and rocks while a few geologists pay attention to minerals crystallized from fluids. In this paper, we present the definition and characteristics of fluid minerals, mineral assemblage and fluid rocks based on many years of research. Our recent study shows that magma may contain large amounts of fluids, originated from fluid concentration during magma evolution, magma-country rock interaction or external sources. Putting forth the concept of fluid mineral shall deepen our understanding of geologic processes hence develop new frontiers in petrologic and ore deposit research. The concept can be useful in mineral exploration and metallogenic prediction.

Key words: fluid minerals, fluid mineral assemblages, fluid rocks