First you need to define how much chi a rock has. At first glance it would seem none, however if you consider the phrase 'stuck between a rock and a hard place' you could deduce that a rock has an equal amount of chi energy as any place considered 'hard' or tough.
Now that we have established how a rock already has plenty of chi energy, we should consider the limits of our own perception. Is a rock a still lump of mineral, or is it in fact moving so fast or in such a manner that we are unable to perceive it? Having established the basic fact of the huge amounts of chi within a rock, I think it's safe to presume that the problem is in our own perception of a rock.
Finally we should consider whether the rock would roll up a hill, or if in fact it is a simple case of moving the hill under it. The hill may obviously consist of a larger quantity of rock, so what we need is a rock with a high quality of chi. Fossilized Giant Squid should do this fine.