What happened around 800 million years after Earth formed to allow rocks to

form?

earth cooled sufficiently.

metamorphic rocks, igneous rocks and sedimentary rocks

Explanation:

metamorphic rocks are made by lots of heat and pressure from the earths crust where they are found. igneous rocks are made by volcanoes from the magma when it cools. sedimentary rocks are made by years and years of sediment coming together and hardening.