Columnar jointing

Imagine playing with a big piece of clay or play-dough. Now, pretend you are making a really tall tower by stacking the clay up higher and higher. Once you have a really tall tower, imagine that you take a knife and carefully cut down through the middle of the tower.

Now, you can see that the clay is no longer one solid piece, but instead it is made up of lots of smaller columns that are all stacked on top of each other. Each column is similar in shape and size to all the other columns.

Columnar jointing happens when lava or hot magma cools down and starts to harden. Just like the clay tower, the lava and magma are made up of lots of individual columns that are all stacked together. As the lava or magma cools, it contracts and starts to crack. These cracks form along specific planes in the substance, which helps create the column shape.

Over time, the lava or magma will keep cooking until it is completely cool and solid. When it is cool, we are left with a beautiful and unique pattern of columns known as columnar jointing. It can be seen at places like the Giant's Causeway in Ireland or in basalt formations like Devil's Postpile in California.