Design your marble horses on paper first. Draw at least three or four sketches that show your horses from different angles. Consider sketching the horses from the front view, left side, right side, rear view and top. Now is the time to make your decision about the details of the statue. Are you attempting to create a realistic, scale model of a horse or a Baroque-style image? Ask yourself if you want the horses' ears forward or back. Will their necks be arched? Will their eyes and nostrils be opened wide in excitement?
Acquire your tools and stone. Find a piece of marble that is already similar to the shape of your horses if possible. If you have the financial means, consider purchasing air-driven hammers. Pneumatic hammers are a much faster way to work your marble. You also want to have oxide paper in various grades, plus rasps and files.
Mark your stone before roughing it out. Use a pencil or crayon to mark the marble because ink can bleed into your stone and leave a permanent mark.
Rough out your marble. In other words, remove the majority of the excess marble with a heavy chisel or power tools like the angle grinder. Be sure to wear your safety equipment during this step. To rough out your stone accurately, avoid trying to slice out big chunks. Remove excess marble by cutting off half-inch-thick slices of stone.
Use your point chisel to refine the sculpture to look like your sketches of horses. Most stone can be worked with a chisel held at a 45-degree angle, but marble is harder and may require a steeper angle. Use you chisel to create lines and crosshatches across the marble, and remove small squares of marble. Then use flat chisels, rasps and files to further refine your marble. At that point your sculpture should really look like horses.
Sand and polish your marble horse statue. Start with the coarser grit sandpapers and use finer grades as you desire. Polishing fluids are your last step to creating a glossy horse statue. Simply rub them on with a clean, very soft cloth.