What causes sand to form?

Sand forms primarily through the weathering and erosion of rocks and minerals, particularly quartz, over long periods. Natural processes like wind, water, and ice break down larger rocks into smaller particles. These particles are then transported and deposited in various environments, such as beaches and riverbeds, where they accumulate and eventually compact to form sand. Additionally, biological processes, such as the breakdown of shells and coral, can also contribute to sand formation in marine environments.