Question: What are the 3 main kinds of rocks?
The 3 kinds of rocks are igneous, sedimentary, and metamorphic.
Igneous rocks are either glassy, fine grained, coarse grained, or porphyritic. Volcanic rocks sometimes have holes in them from escaping gases (called vesicles). Sometimes the holes are filled with minerals, and then the rock is amygdaloidal. Rocks that have vesicles are usually fine grained like basalt. Volcanic rocks are fine grained, glassy, or porphyritic. Glassy texture is easy. The rock is usually black obsidian. Most volcanic lavas are fine grained or porphyritic. …
