Answer
When exposed to heat and pressure, slate turns into Schist by metamorphosis.
Step-by-step explanation
Slate is a fine grained foliated metamorphic rock formed from the metamorphosis of mudstone or shale changes. By continuous heating and pressure , Schist is formed from slate and is made up of flaky scales and can split into pieces with ease. Schist contains large crystals that reflect light making it to have high luster.