Living stones
These strange stones, to be more precise, the small creatures that live on the stones (cyanobacteria) are the first creatures to discover photosynthesis as a form of energy and thus produce oxygen.
An amazing way that these stones grow very slowly and thanks to which we exist at all.
They are responsible for the fact that life could initially explode underwater. Oxygen, in turn, self-generated ozone and with it living beings from the water could go to land, which otherwise the UV radiation would have been destroyed immediately. Oxygen, on the other hand, is a highly flammable gas which helped our ancestors discover fire, allowing early humans to cook their food and digest and absorb the nutrients better. As a result, the brain grew and we became intelligent.