Stone carving is an activity where pieces of rough natural stone are shaped by the controlled removal of stone. Owing to the permanence of the material, stone work has survived which was created during our prehistory.
Stone carving is one of the processes which may be used by an artist when creating a sculpture. The term also refers to the activity of masons in dressing stone blocks for use in architecture, building or civil engineering. It is also a phrase used by archeologists, historians, and anthropologists to describe the activity involved in making some types of petroglyphs.
The development of iron made possible stone carging tools, such as chisels, drills and saws made from steel, that were capable of being hardened and tempered to a state hard enough to cut stone without deforming, while not being so brittle as to shatter.
Process of carving
Carving stone into sculpture is an activity older than civilization itself. Prehistoric sculpture were usually human forms. The process begins with the selection of a stone for carving. Some artists use the stone itself as inspiration. When ready to carve, the artist usually begins by knocking off large portions of unwanted stone. This is the "roughing out" stage of the sculpting process. For this task they may select a point chisel, which is a long, hefty piece of steel with a point at one end and a broad striking surface at the other. A pitching tool may also be used at this early stage, what is useful for splitting the stone and removing large, unwanted chunks.
Once the general shape of the statue has been determined, the sculptor uses other tools to refine the figure. A toothed chisel or claw chisel has multiple gouging surfaces which create parallel lines in the stone. These tools are generally used to add texture to the figure.
The final stage of the carving process is polishing. Sandpaper can be used as a first step. Emery, a stone that is harder and rougher tan the sculpture, is also used in the finishing process.
Stone can be dug from the surface and carved with hand tools. Stone is more durable than wood, and carvings in stone last much longer than wooden artifacts. Stone comes in many varieties and artists have abundant choices in color, quality and relative hardness.
Soft stones such as chalk, soapstone, pumice adn tufa can be easily carved with found items such as harder stone or in the case o chalk even fingernail.
Limestones and marbles can be worked using abrasives and simple iron tools.
Granite, basalt and some metamorphic stone is difficult to carve even with iron or steel tools.
Stone shaping and tools
Basic stone carving tools fall into five categories:
- Percussion tools for hitting -such as mallets, axes, adzes, bouchards and toothed hammers.
- Tools for rough shaping of stone, to form a block the size needed for the carving. These include feathers and wedges and pitching tools.
- Chisels for cutting - such as lettering chisesl, points, pitching tools, and claw chisels. Chisels, in turn, may be handheld and hammered or pneumatic powered.
- Diamond tools which include burrs, cup wheels, and blades mounted on a host of power tools. These are used sometimes through the entire carving process from rough work to the final finish.
- Abrasives for material removals - such as carborundum blocks, drills, saws, grinding and cutting wheels, water-abrasive machinery and dressing tools