There are large pools of molten rocks and minerals inside the Earth. As the molten rock moves toward the surface of the Earth, it cools. Layers of rock above this magma are like blankets that hold in the heat, allowing it to cool slowly while still beneath the Earth’s surface. Rocks can be formed from the magma that has cooled and hardened into solid form. Rocks can also form when hot lava comes out of the Earth and cools on its surface. These types of rocks are called igneous rocks. When molten rock begins to cool, it changes in both form and texture. Some minerals form specific geometrical shapes and become crystals as they harden.
Basalt is a fine grained igneous rock that poured out in massive liquid sheets and cooled into gray rock formations. Granite is a common igneous rock made up of different types of minerals in the form of crystals: quartz, feldspar and mica are three examples. Rhyolite is also an igneous rock made up of the same minerals as granite but it has very small crystals compared with the larger ones found in granite. As a result, their textures and appearances are very different.
Question
Other than basalt, granite and rhyolite, what are some other igneous rocks? You may need to do a little research.
