Concept:
Igneous rocks are formed by the cooling and solidification of molten magma or lava.
Step 1: Sandstone is a sedimentary rock.
Step 2: Marble is a metamorphic rock formed from limestone under heat and pressure.
Step 3: Limestone is a sedimentary rock.
Step 4: Basalt is formed from cooled lava and is an igneous rock.
Therefore, the igneous rock among the options is:
\[
\boxed{\text{Basalt}}
\]