Igneous rocks are, quite literally, born from fire. They form from what geologists call "melt"—basically, rock that has been heated so much it turns into a liquid. Deep inside the Earth, this liquid rock is called magma. As soon as it erupts or flows onto the surface? It becomes lava. Same stuff, just different zip codes.
Think of magma as the Earth's secret sauce, simmering at temperatures between 700°C and 1,300°C. That’s hotter than your pizza oven—way hotter. This molten mixture is composed of melted minerals, dissolved gases, and some solid crystals that haven't quite given up yet. It’s a chaotic, hot soup waiting to cool down.
Where Does the Melt Come From?
You might assume the Earth's core is a big liquid ball, but that’s a myth. Most magma is created in the mantle, the layer between the core and the crust. Heat and pressure changes cause solid rock to melt partially—like a butter pat left on a hot engine block.
Water and carbon dioxide also help lower the melting point, acting like a chemical crowbar. This process happens in zones where tectonic plates collide or pull apart. It’s not random; the planet has its own recipe book.
