No, shale is not an igneous rock. It is classified as a sedimentary rock.
Shale forms from the accumulation of mud, silt, and clay that compact over time, usually in environments like river deltas, lakes, or ocean floors. These tiny particles can come from the weathering of other rocks. As these sediments settle and undergo lithification—a process where sediments are compressed and cemented together—they create shale.
On the other hand, igneous rocks originate from the cooling and solidification of molten rock, either from magma beneath the Earth’s surface or lava that erupts onto the surface. Examples of igneous rocks include granite and basalt. The fundamental differences in their formation processes clearly indicate that shale does not belong to the igneous rock category.