Sand itself is not a rock but rather a granular material composed of small particles of minerals, rocks, or organic remains. When these sand grains become compacted and cemented together through a process called lithification, they form a type of sedimentary rock known as sandstone. Thus, sand is the loose granular material, and sandstone is the rock formed from that sand.

What Sand Is

• Sand consists of individual grains that are typically between 0.063 to 2 mm in size.
• These grains can be mineral particles (mostly quartz), fragments of rocks, or biogenic materials like shells or coral remains.

• Sand grains originate mostly from the weathering and erosion of preexisting rocks, plus some contribution from biological sources or chemical processes.

How Sand Becomes Rock

• Through lithification, which involves compaction and cementation, sand grains fuse to form sedimentary rock.
• The resultant rock is called sandstone, a common type of sedimentary rock composed primarily of sand-sized particles.

In summary, sand itself is not a rock, but it can become a rock when it is consolidated into sandstone.