Adhesive peels off stones after a week. I wire brushed the stones before applying them, so I think I had a better chance of holding them. The glue didn't stick to any of the stones I was trying to glue. I ended up using a pre-mixed grout which works better and provides more volume to fill voids in irregularly shaped rocks. I think this is more suitable for sticking the facsimile stone on another flat and porous surface.