I don't do M&P soap but 3D molding is one of the best attributes of doing M&P. Simply search Google for "3D Soap Molds" and you'll have ample sources of suppliers, techniques, etc. Same for youtube for free lessons your daughter can use for technique.
Thank you for replying. I am familiar with the 3D molds. So, you do not think there is any way to actually hand-form the soap at any point in the process. My daughter wanted to make a wheat germ soap that looks like rocks - and she wanted the "rougher" look for a hand formed ball to make it appear more natural and "rock-like".
I really wish I could help but I've never made M&P soap. But.....this video looks like you could alter it a bit to make rocks. Skip ahead to where the lady is making the ice cream 'scoops'. I think perhaps you could change the color and using a scoop could start the rocks and if need be, use your fingers to change the final surface effects to your taste. If nothing else, perhaps the recipe she gives for the scoops will be sufficient for it to be the right consistency for you to manually mold it in a way different from scooping if you don't prefer that method. [ame]http://www.youtube.com/watch?v=B1ffyjFU6wk[/ame]
It will take a few trial and errors to do. But wait until it starts to form a skin before you mold it with your hands. Though you lose some soap base in the process because some will stick to your hands. Keep notes and measure the temperature until you find out the best time to mold it with your bare hands.
It may be easier to use a loaf pan and pour a few inches, then after it has cooled and set up to carve rocks our with a knife. I carved MP into seaglass for Christmas gifts. That is - if your daughter is not too young to use a knife. If she is too young, you can do and and she can watch.
There's a coal soap tutorial that might work for the rocks, let me see if I can find it....
Here it is, while her soaps are round, your daughter could certainly change the shape to be more random, and of course the color choice is hers as well. For multiple color rocks, just make smaller batches with different colors then mix them together in her hands, not in the bowls.
I use an egg beater whip thing to whip it when it's melted. As you whip it, it starts to incorporate air into it. If you stop whipping it, it will liquidize again, so just keep whipping it until it's solid.