Granite

rocks · geology · Earth science · igneous

Born from magma. Granite forms when hot, melted rock called magma sits underground and cools down very slowly over thousands of years. As it cools, different minerals crystallize and lock together into the speckled rock we see.

Made of crystals. Granite is packed with four main minerals: quartz, feldspar, mica, and plagioclase. These minerals form visible crystals, which is why granite looks speckled with white, pink, gray, and shiny flakes.

Builds continents. Granite is super common in Earth's continental crust and makes up huge underground formations called batholiths that can stretch for hundreds of kilometers. It's one of the strongest rocks that holds up entire landmasses.

Hard and useful. Because granite is so tough and beautiful, humans have used it for thousands of years to build monuments, sculptures, countertops, and buildings. It's one of the most popular rocks for construction and decoration.

Cooled slowly. The key to granite's strength is that it cooled underground at a slow pace, allowing big crystals to grow. If magma cooled quickly above ground, it would form different, weaker rocks instead.