There are theories that equate information processing (integration/differentiation) with consciousness.
It maps well with what happens in your brain, where too little or too much functional connectivity maps to loss of consciousness (think anesthesia and epilepsy).
Rocks also have complex internal structure that responds to external influence, e.g. atoms vibrating in their crystal lattices depending on heat and pressure. Maybe there is a Boltzmann consciousness inside the rock when you're picking it up. What is "information" and what is noise is a matter of interpretation.
Rocks have random structure, not complex structure. Randomness does not entail consciousness. A feature of consciousness is that it is informative: it informs you about the external state of the world or about internal processes. But a random configuration of molecules carry no information. (A random string is information but it doesn't carry information, i.e. mutual information with another structure.)
It maps well with what happens in your brain, where too little or too much functional connectivity maps to loss of consciousness (think anesthesia and epilepsy).