Granite is a hard, crystalline igneous rock. The hardness of granite varies depending on the type and composition of the granite. On the Mohs scale of mineral hardness, granite typically ranges from 6 to 7. This means that granite can scratch glass (Mohs hardness 5), but it cannot scratch topaz (Mohs hardness 8). The primary minerals in granite are feldspar, quartz, mica, and amphibole. The hardness of these minerals contribute to the overall hardness of granite. Feldspar and quartz are both rated 6-7 on the Mohs scale, mica is 2-3, and amphibole is 5-6. The relative abundance of these minerals in a particular granite will influence the overall hardness of the rock.