lesson
Updated 6 days ago ยท 1 view
Did you know that every pebble in your pocket and every giant mountain peak belongs to one of just three rock families?
Geologists, the scientists who study the Earth, group all rocks based on how they were made: by fiery heat, by stacked layers, or by intense pressure.
Let's meet the first family born straight from melted liquid rock.
Igneous Rocks: Born from Fire
Deep beneath Earth's crust, rock gets so super-hot that it melts into a glowing liquid called magma.
When that liquid rock cools and freezes solid, it forms an igneous rock (from the Latin word ignis, which means fire).
๐A clean, colorful diagram showing how igneous rocks form. On the left, an erupting volcano shows red lava cooling quickly on the surface into dark Basalt and bubbly Pumice (labeled 'Extrusive / Fast Cooling'). Underground, a magma chamber slowly cools into speckled Granite with visible crystal grains (labeled 'Intrusive / Slow Cooling'). Use warm red/orange accents (#ff6b4a), dark gray rock (#333), and clear badge labels on white card panels (#ffffff). Responsive layout at 350px width.
If magma stays underground, it cools slowly over thousands of years to make speckly granite with big mineral crystals.
If it shoots out of a volcano as lava, it cools quickly in the open air, forming dark basalt or spongy pumice with trapped gas bubbles.
What happens when rain, wind, and rivers grind these hard rocks down into tiny grains of sand and mud over millions of years?
Sedimentary Rocks: Built in Layers
Tiny bits of broken rock, sand, and ocean shells are called sediments.
Rivers wash sediments into lakes and oceans, where they pile up at the bottom in heavy, flat blankets.