Sandstone is a sedimentary rock, not an igneous rock.

Igneous rocks are formed from the cooling and solidification of magma or lava. Sedimentary rocks, like sandstone, are formed from the accumulation and cementation of sediments, which are often derived from the weathering and erosion of pre-existing rocks (including igneous rocks).

Here's how sandstone forms:

1. Weathering and Erosion: Igneous rocks, along with other rock types, are broken down by wind, water, and ice into smaller fragments.

2. Transportation: These fragments, including sand-sized grains, are transported by wind, water, or ice.

3. Deposition: When the transporting forces lose energy, the sand grains settle and accumulate in layers.

4. Compaction: The weight of overlying sediment compresses the sand grains, squeezing out water and air.

5. Cementation: Dissolved minerals in groundwater precipitate between the sand grains, acting as a cement that binds them together, forming solid sandstone.

So, while igneous rocks can be the source of the sand grains that make up sandstone, sandstone itself is a sedimentary rock.