Rock is sculpted and shaped in a number of ways for a number of different purposes. To do this successfully, masons and artists who use rock in their sculptures must use specific tools to effectively carve and shape the rock to their liking. The tool used to specifically grind rock are power tools, until the end when fine shaping and sanding is necessary.
Grinders and minigrinders are tools that look like power drills except for the fact that they have a round grinding disc of different grades of roughness which can be attached, allowing the tool to cut and shape a wide variety of rocks. These discs are best used on most softer stones, like sandstone and lime. For harder stones like granite, a diamond grinding blade should be used so that the other discs are worn out entirely. Most blades must be used to cut in a perfectly straight line or else the blade will kick back and damage the blade and machine and possibly damage you as well.
A die grinder is used for carving small details into softer pieces of stone, like soapstone or alabaster once the large cuts or shapes have been made with the larger grinder. This tool resembles a power drill as well but with a small cone-shaped grinding head that spins at high speeds and allows you to cut and carve the stone in all desired directions. The shape of these heads also allows you to get into crevices or holes you would otherwise never be able to reach with a standard grinder.
Once the initial and detail-oriented grinding has been completed, another form of grinding and shaping of the stone takes place, putting the finishing touches on its surface. With a file or sandpaper on smaller, decorative stones, one can polish the dust or shave any rough edges away by hand in an efficient manner. However, when having to polish or sand down large surfaces, like a large statue or a stone floor or patio, a polisher would probably be your best bet. This looks like a disc sander but a bit more industrial in design, using polishing discs which range from sandpaper grit to Velcro.