Question: what is the difference between fine grained and coarse grained igneous rock?
Answer: Coarse-grained igneous rocks have individual grains (crystals) that are visible to the naked eye. Grains can range from millimeters to centimeters in diameter. The grains form an interlocking network. Fine-grained igneous rocks have small grains, less than a millimeter across, that are invisible to the naked eye.