Anyone use shale rock for the basking spot?? I was going to try it out but I thought I would just asked before I even bought some. I have the top of my retes stack painted black but with winter comming I think shale on the top would hold the heat better. I use a different kind of rock for my beardies in the winter and it seems to suck up the heat and hold it better than the black painted wood. I cannot find anymore of this rock though so I think shale will be somewhat similar.