Magic Forums

The other day, while discussing our newest project, (Runes) My friend and I were having trouble sorting out the materials. Runes typically call for wood, however, living in a city has its ups and downs, and one of those downs is definitely the lack of trees. However, after a long while of fruitless ideas, my friend got the idea of just plucking a few stones from the river and alleys, and just painting on those along with all the typical steps. Myself, thought this was a wonderful idea, as the flowing water near them could have strong energies in it. However I'm not sure if these stone runes would work well, if at all. So I suppose my question would be, how do you all think this might work if at all? Please let me know. Experiences, stories, side notes, etc. are very welcome.