The earth's crust has several layers composed of three types of rocks, which are formed by the mixture of different materials. These rocks can be magmatic, also called igneous, sedimentary or metamorphic.
Magmatic or igneous rocks
Magmatic or igneous rocks (fiery comes from Latin and means "fire") they originate from the interior of the earth, where they are fused at very high temperatures. In volcano eruptions, these rocks are thrown from the interior of the earth to the surface. They then undergo rapid cooling and solidify. Other times they are near the surface, where they cool slowly and also solidify.
- O basalt It is a dark rock widely used for paving sidewalks, streets and roads and comes from the rapid cooling of magma.
In Rio Grande do Sul, we find the cliffs of Torres, formed by basalt.
The dark strips of the famous Copacabana sidewalks in Rio de Janeiro are formed by basalt.
- THE pumice stone, generated after rapid cooling in contact with water forming a rock full of pores or holes due to the outflow of gases. It looks like a "hardened foam".
Pumice stone is used to polish objects and soften the skin.