fossils....?

Question

just curious, but how do bones turn into rock? I thought chemicals were stable unless disrupted by electrical current. How does this process work?

Answer 1

In some cases, the fossils form from the bones of the animals by replacement. Bones are hollow - they have a space in the center, and the material of the bones has microscopic spaces in it. The spaces can be filled with minerals which are dissolved in the ground water and slowly crystallize in the spaces over many thousands of years. And, the actual material of the bones can be replaced by the minerals from the surrounding rocks. The fossils may be really a cast of the bones, in the same sense as you would cast a statue in a mold in a metal foundry. The bones act as the mold that the minerals are formed in.
Not all fossils are the same. There are different materials involved, depending on where and how the fossils were formed.