Texture in geology refers to the physical appearance or character of a rock, such as grain size, shape, arrangement, and pattern at both the megascopic or microscopic surface feature level. This includes the geometric aspects and relations amongst the component particles or crystals which is called the crystallographic texture or preferred orientation. The term microstructure is preferred by some petrographers.[1] Textures can be quantified in many ways.[2] The most common parameter is the crystal size distribution.