The Sonoran Desert is rich in granite, a durable igneous rock that forms the rugged mountains and landscapes of the region.

Granite is the most common rock type in the Sonoran Desert, formed from slow-cooling magma beneath the Earth's surface. Over millions of years, erosion has exposed large granite formations, creating rocky hills, boulder fields, and rugged cliffs seen across Arizona, California, and Mexico. This rock is highly resistant to weathering, making it a key feature of the desert's geology. While other rock types like basalt and limestone exist, granite dominates the mountain ranges and desert landscapes, influencing soil composition and providing habitats for various desert species.