Final answer:
Coarse grain is a term used to describe a rock's grain pattern. This refers to rocks that have large grains or crystals that are generally larger than 1 millimeter in size. These rocks are hard and can scratch glass.
Step-by-step explanation:
Coarse grain is a term used to describe a rock's grain pattern. It refers to rocks that have large grains or crystals that are generally larger than 1 millimeter in size. These crystals are big enough to identify individual minerals and often have straight edges that interlock with each other. The texture of coarse-grained rocks is generally uniform, and they are usually hard and can even scratch glass.