This paper is the result of mineral exploration engineering.

Objective Greisen commonly generates on the top of the granitic plutons and are the important carriers of non-ferrous metals (W and Sn) and rare metals (Li, Be, Nb, and Ta). It has a gradual transition relationship with the underlying granite and often extends outsides the greisen dykes that are perpendicular to the greisen. At present, there is no clear classification of the genetic types of the greisen, so the formation processes of various greisen types and their corresponding mineralization mechanisms have not been explained well.

Methods This paper collects publicly published data and related literature from both domestic and international sources, and sorts out and summarizes the morphological occurrence, geochemistry, and mineralization characteristics of greisen at the top of 35 ore-bearing granitic plutons in China.

Results We classified the different greisens to three genetic types and proposed the corresponding diagenetic and metallogenic processes: (1) Greisen is the product that the granitic magma become cooling and consolidation in an ultra-shallow environment. It formed in a pure magmatic system and included the rare metal mineralization; (2) Greisen is the product of melt-fluid interaction. The fluids contain not only the magmatic hydrothermal fluids but also the external fluids. Tungsten-tin orebodies usually formed in such greisens, which were the results of interaction between the highly fractionated magmas and external fluids in an open magma system; (3) Greisen is also the product of melt-fluid interaction. Here the fluids were hydrothermal fluids exsolved from the magma itself without the addition of external fluids. Rare metals are enriched in such greisens and are the products of the extremely fractionated magmas and magmatic hydrothermal fluids in a closed magma system.

Conclusions There are obvious differences between three genetic types of greisens and three metallogenic properties. Understanding the differences among various types is in favour of further exploration and prospecting of different types of deposits based on their genetic types in the future.