ABSTRACT
Small solid-phase inclusions are commonly observed in metamorphic minerals. They can develop either by exsolution of a solute phase during cooling, by enclosure of residual foreign phases during porphyroblast growth, or due to incomplete pseudomorphing of an early phase by a later one. In certain high-grade rocks two or more phases may crystallise simultaneously to give rise to distinctive symplectic intergrowths. In granulite facies rocks, the development of concentric coronas of one or more phases around a core of another phase is a commonly observed feature. The characteristics of these various microstructures and the processes involved in their development will now be examined.
