Sandstone is primarily composed of which material?

Sandstone is primarily composed of cemented sand, which consists of sand-sized particles that have been compacted and bound together by various types of cement, typically silica, calcium carbonate, or iron oxide. The size and composition of the grains give sandstone its distinctive characteristics and sedimentary structure.

In contrast to other materials listed, cemented clay results in claystone, while cemented cobbles would form conglomerate rock, and cemented silt would create siltstone. Each of these rocks has different properties and formation processes, highlighting the unique nature of sandstone as a sedimentary rock formed from sand particles. Thus, the correct answer accurately reflects the primary makeup of sandstone, distinguishing it from these other sedimentary rock types.