He'll be turning 14, and is into rocks and minerals, so what could be more appropriate than an edible 'rock'? Years ago when I was a volunteer art teacher, one of my favourite projects in grade six was the making of paper rocks and minerals. I had drawn up crystal patterns for various rocks and minerals, and they were printed onto card stock. The kids made the crystals and covered them with Podgy & tissue paper. Then the crystals were glued onto a 'paper rock base' made of crumpled construction paper slathered with wallpaper paste. They looked incredibly believable....
the pieces together with royal icing, I did a little sanding to smooth everything out a little....
diluted purple food colouring, and put them over a heating duct to dry....