Medical Definition of amnesia. 1: loss of memory sometimes including the memory of personal identity due to brain injury, shock, fatigue, repression, or illness or sometimes induced by anesthesia a period of amnesia after the wreck.
Shale is a fine-grained sedimentary rock that forms from the compaction of silt and clay-size mineral particles that we commonly call mud. This composition places shale in a category of sedimentary rocks known as mudstones.
Granite is an example of this type of igneous rock. Small crystals (fine texture) or no crystals (glassy texture) means that the rock cooled fast. These rocks usually form during a volcanic eruption and are called extrusive igneous rocks. Basalt is an example of this type of igneous rock.