When a chemical relaxer and heat applied to a curly hair, the protein present inside your hair get denature. Due to this denaturation of protein in the hair, the hair are soft and flexible which can be converted into any direction and different styles can be done. If chemical perm or relaxer is applied to straight hairs, it also denature the protein and make the hair curly.
The magma cools very slowly. As magma cools minerals are formed into an interlocking arrangement producing an igneous rock. As magma cools it undergoes reactions that form minerals. The rate of cooling is very important.