砂 (suna) is the Japanese word for "sand." It consists of small, granular particles that are typically formed from the weathering and erosion of rocks. Sand is commonly found on beaches, riverbeds, and deserts, and it plays a crucial role in various ecosystems. In construction, 砂 is an essential material used in making concrete and mortar. It is also used in glass production and as a filtration medium in water treatment. The size and composition of sand grains can vary, influencing its properties and applications in different industries.