How do you know if a rock is an igneous rock?

Answer 1

Igneous rock is magma (or lava) that has cooled, hardened, and solidified. It is recognized by it's generally smooth texture, high mass (basically a rock a certain size will weigh more than you'd expect just by looking at it), and wavy form-remember, it is solidified magma.

Answer 2

The rock crystallizes and how it cooled from what is made of

Answer 3

Geologists classify igneous rocks based on their origin, texture and mineral composition. Rhyolite, Granite, Pegmatite, and Porphry are all igneous rocks