Rocks

Rocks are interesting to make. The two things to consider are texture and color. I make rock formations with a styrofoam beadboard base. I get the general shape I want, then paint it with plaster. This gives some heft to the block and is also a good base for paint.

Plaster can be molded into a lot of shapes if the consistency is fairly stiff. It can also be painted on thin if it is runny. There is a fine line between too wet and too stiff. Another method is to put some plaster powder down and spray it with water. This makes a nice migmatite effect.

A lot of the mountains are made of granite, so my mountain loop terrain is granite. The granite in the Colorado Front Range is usually kind of pinkish, sometimes orangy. There are quite a few variations, but I have tried to get the gist of the local rocks.

Down south along the Platte and along the Cripple Creek Road the granite is of the Pikes Peak batholith. This is mostly pinkish stuff and the youngest of the granite intrusions along the Front Range. It often weathers in rounded humps through foliation from heating and cooling. There are also joint systems, usually three, that increase the weathering and make some very interesting formations, notably the Cathedral Park formations along the old CS&CCD RR between Colorado Springs and Cripple Creek.

The image above is my pathetic attempt at mimicking this type of weathering. I tried to accomplish this by making small blocks of styrofoam, sanding down the edges, assembling them with double-stick tape, then coating them with plaster. I cut the minor joints with a knife after the plaster had set, but I should have tried to do this as the plaster was setting, as this result shows a lot of subsidiary cracks.

You will note the talus below the knob; this is created with cat litter fixed with plaster and Mod Podge. Cat litter has many uses as ballast, coal, or other kinds of aggregate. It also has some weight to it, so it is good a loads in the ore cars and gondolas.

Much of the granite farther north is Boulder Creek granodiorite and is not as blocky as the Pikes Peak outcrops. I tried to show some ore veins and such, also other intrusions and a variety of textures. I've noticed that getting the base color about right, then washing it with other shades seems to give the right effect.

You can also get texture by adding sand or other types of aggregate to the wet plaster or painting with Mod Podge and sprinkling on top. I find it is difficult to model a specific type of formation, so I apply the Jackson Pollack approach and just slop stuff on until it turns into something; I think this is how nature does it and it has worked well for me so far.

Strata can be most interesting, but is a little difficult to do. I do not have the knack for this, but my good friend Stanley J. Weddle is particularly good at making formations from styrofoam beadboard sheet; most of the shapes in this section are done by him. I do the same as with the granite: coat with plaster and then paint.

I particularly like the flatiron formation faulted over the lower strata.

This last formation is supposed to be massive limestone overlain by some sandstone strata.