Petrifaction

Have you ever seen a fossil or a rock that looks like a bone? That's called petrifaction.

When things like plants, animals or bones get buried in a special kind of mud or sediment, it can turn into a rock over a really long time. This process is called petrifaction.

First, the things that get buried have to be covered with a lot of soft, muddy sediment. Then, over thousands of years, water can seep into the sediment and bring in minerals like silica or calcite. These minerals fill in the tiny spaces in the bones or plants and slowly replace their original material.

As the material is replaced by minerals, the original shape of the plant or animal is preserved, but it becomes a rock. This is really amazing because sometimes we can find fossils of animals that lived millions of years ago and they still look like they would have when they were alive.

So that's what petrifaction is – the slow process of turning something like a bone or plant into a rock over a very long time.