Final answer:
Granite is described as a coarse-grained igneous rock with large grains that allow for the identification of individual minerals. These grains have shiny, flat, interlocking surfaces and contribute to the rock's uniform texture.
Step-by-step explanation:
The grain shape of a rock such as granite is typically described as coarse-grained. This relates to the size and interlocking nature of the crystals that make up the rock. In granite, these grains are generally large enough to identify the mineral components, which include quartz, feldspars, and mica. Granite's crystals can range in size, usually larger than 1 millimeter and can extend to about an inch, with shiny, flat surfaces that fit together like pieces of a puzzle having straight edges. These minerals are hard enough to scratch glass, and the overall texture of granite is uniform.