Under this heading are mainly those materials that have formed through a process of crystallization of an original liquid molten rock solution (Magma). The resulting wide range of mineral types, their structures, colours, shapes, sizes and distribution, is governed by the original chemical composition of the liquid phase and the changing, temperature, pressure and chemical environments that the molten body goes through as it cools to become solid rock.
In general the crystalline mineral structure of granite is both hard and durable which in terms of construction usage make such materials more hardwearing than the majority of decorative marbles, limestone and sandstone.