A company here in Hawaii called Big Rock makes what they call moss rock veneer. I've used it on my mini pond and its all over Ala Moana shopping center planter/ponds. Its very easy to work with. Just use the dye mortor mix they recomend and cement to cmu wall surface. Makes awesome ponds that are easy to build as the pond is above ground with the cmu structure for the pond wall and the moss rock veneer covers all pond liner material. Yes it is a great buisness.