Stone carving

The act of shaping stone materials Not to be confused with petroglyph or sculpture.

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 or past time.

Read more

Work carried out by paleolithic societies to create stone tools is more often referred to as knapping. Stone carving that is done to produce lettering is more often referred to as lettering. The process of removing stone from the earth is called mining or quarrying.

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 archaeologists, historians, and anthropologists to describe the activity involved in making some types of petroglyphs.

The earliest known works of representational art are stone carvings. Often marks carved into rock or petroglyphs will survive where painted work will not. Prehistoric Venus figurines such as the Venus of Berekhat Ram may be as old as 250,000 years[citation needed], and are carved in stones such as tuff and limestone.

These earliest examples of the stone carving are the result of hitting or scratching a softer stone with a harder one, although sometimes more resilient materials such as antlers are known to have been used for relatively soft stone. Another early technique was to use an abrasive that was rubbed on the stone to remove the unwanted area. Prior to the discovery of steel by any culture, all stone carving was carried out by using an abrasion technique, following rough hewing of the stone block using hammers. The reason for this is that bronze, the hardest available metal until steel, is not hard enough to work any but the softest stone. The Ancient Greeks used the ductility of bronze to trap small granules of carborundum, that are naturally occurring on the island of Milos, thus making a very efficient file for abrading the stone.

The development of iron made possible stone carving 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. Carving tools have changed little since then.

Modern, industrial, large quantity techniques still rely heavily on abrasion to cut and remove stone, although at a significantly faster rate with processes such as water erosion and diamond saw cutting.

One modern stone carving technique uses a new process: The technique of applying sudden high temperature to the surface. The expansion of the top surface due to the sudden increase in temperature causes it to break away. On a small scale, Oxy-acetylene torches are used. On an industrial scale, lasers are used. On a massive scale, carvings such as the Crazy Horse Memorial carved from the Harney Peak granite of Mount Rushmore and the Confederate Memorial Park in Albany, Georgia are produced using jet heat torches.

Main articles: Stone sculpture and Architectural sculpture

Carving stone into sculpture is an activity older than civilization itself. Prehistoric sculptures were usually human forms, such as the Venus of Willendorf and the faceless statues of the Cycladic cultures. Later cultures devised animal, human-animal and abstract forms in stone. The earliest cultures used abrasive techniques, and modern technology employs pneumatic hammers and other devices. But for most of human history, sculptors used hammer and chisel as the basic tools for carving stone.

The process begins with the selection of a stone for carving. Some artists use the stone itself as inspiration; the Renaissance artist Michelangelo claimed that his job was to free the human form trapped inside the block. Other artists begin with a form already in mind and find a stone to complement their vision. The sculptor may begin by forming a model in clay or wax, sketching the form of the statue on paper or drawing a general outline of the statue on the stone itself.

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; which is a wedge-shaped chisel with a broad, flat edge. The pitching tool is useful for splitting the stone and removing large, unwanted chunks. Those two chisels are used in combination with a masons driving hammer.

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. An artist might mark out specific lines by using calipers to measure an area of stone to be addressed, and marking the removal area with pencil, charcoal or chalk. The stone carver generally uses a shallower stroke at this point in the process, usually in combination with a wooden mallet.

Eventually the sculptor has changed the stone from a rough block into the general shape of the finished statue. Tools called rasps and rifflers are then used to enhance the shape into its final form. A rasp is a flat, steel tool with a coarse surface. The sculptor uses broad, sweeping strokes to remove excess stone as small chips or dust. A riffler is a smaller variation of the rasp, which can be used to create details such as folds of clothing or locks of hair.

The final stage of the carving process is polishing. Sandpaper can be used as a first step in the polishing process, or sand cloth. Emery, a stone that is harder and rougher than the sculpture media, is also used in the finishing process. This abrading, or wearing away, brings out the color of the stone, reveals patterns in the surface and adds a sheen. Tin and iron oxides are often used to give the stone a highly reflective exterior.

Sculptures can be carved via either the direct or the indirect carving method. Indirect carving is a way of carving by using an accurate clay, wax or plaster model, which is then copied with the use of a compass or proportional dividers[1] or a pointing machine. The direct carving method is a way of carving in a more intuitive way, without first making an elaborate model. Sometimes a sketch on paper or a rough clay draft is made.

Stone has been used for carving since ancient times for many reasons. Most types of stone are easier to find than metal ores, which have to be mined and smelted. 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 stone such as chalk, soapstone, pumice and Tufa can be easily carved with found items such as harder stone or in the case of chalk even the 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; usually tungsten carbide tipped tools are used, although abrasives still work well. Modern techniques often use abrasives attached to machine tools to cut the stone.

Precious and semi-precious gemstones are also carved into delicate shapes for jewellery or larger items, and polished; this is sometimes referred to as lapidary, although strictly speaking lapidary refers to cutting and polishing alone.

Featured content:
How does a flow meter operate?
5 Different Types of Deer Fencing and How to Choose One
11 Factors to Consider When Buying Oil Seals

For more information, please visit jm.

When worked, some stones release dust that can damage lungs (silica crystals are usually to blame), so a respirator is sometimes needed.

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 chisels, 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 such as French and English drags.

More advanced processes, such as laser cutting and jet torches, use sudden high temperature with a combination of cooling water to spall flakes of stone. Other modern processes may involve diamond-wire machines or other large scale production equipment to remove large sections of undesired stone.

The use of chisels for stone carving is possible in several ways. Two are:

• The mason's stroke, in which a flat chisel is used at approximately 90 degrees to the surface in an organized sweep. It shatters the stone beneath it and each successive pass lowers the surface.
• The lettering stroke, in which the chisel is used along the surface at approximately 30 degrees to cut beneath the existing surface.

There are many types and styles of stone carving tools, each carver will decide for themselves which tools to use. Traditionalists might use hand tools only.

• Lettering chisels for incising small strokes create the details of letters in larger applications.
• Fishtail carving chisels are used to create pockets, valleys and for intricate carving, whilst providing good visibility around the stone.
• Masonry chisels are used for the general shaping of stones.
• Stone point tools are used to rough out the surface of the stone.
• Stone claw tools are used to remove the peaks and troughs left from the previously used tools.
• Stone pitching tools are used to remove large quantities of stone.
• Stone nickers are used to split stones by tracing a line along the stone with progressive strikes until the stone breaks along the line.

Powered pneumatic hammers make the hard work easier. Progress on shaping stone is faster with pneumatic carving tools. Air hammers (such as Cuturi) place many thousands of impacts per minute upon the end of the tool, which would usually be manufactured or modified to suit the purpose. This type of tool creates the ability to 'shave' the stone, providing a smooth and consistent stroke, allowing for larger surfaces to be worked.

Among modern tool types, there are two main stone carving chisels:

• Heat treated high carbon steel tools - Generally forged
• Tungsten carbide tipped tools - Generally forged, slotted, and carbide inserts brazed in to provide a harder and longer-wearing cutting edge.

• Using plug and feathers to split a block of marble from the quarry
• Carrara marble quarry
• Pitching tool used in preliminary rough shaping blocks of stone
• Carved flower on stone, ancient work, Archaeological museum of Jaffna, Sri Lanka
• Carved sculpture, ancient work, from Chichen Itza, Mexico
• A famous khachkar at Goshavank Armenia
• Diamond blade and bit method: 3D carved slate and travertine Breadfruit wall mural by Janna Morrison, , Maui, Hawaii

• Chalk carving
• List of colossal sculptures in situ
• Khachkar
• Megalith
• Rock-cut architecture
• Stone sculpture
• Stonemasonry
• The Stonemason ( book)
• Songjiang Tangjing Building

Arguably the oldest surviving form of artistic expression is stone carving, with tens of thousands of years of history behind its basic techniques and concepts. Many aspects of human culture's past are now only visible through the lens of ancient stone carvings. This is due to the adaptability and durability of the stone. Early or primitive examples of stone carving include megalithic steles, ancient inscriptions, and carved prehistoric figures. The practice of stone carving and the making of stone carving developed from these humble origins into one of the most fundamental components of the art of sculpture.

How are stone sculptures carved?

Stone is traditionally worked using hand tools, mainly hammers and chisels. The use of tools and skills has enabled artists to perform nearly every type of stone throughout history. Natural stone carvings are not made exclusively with these tools, but they are undoubtedly the most common.

Besides hammers and chisels, artists now have a plethora of tools to create their work. Some artists now use pneumatic chisels, diamond saw blades, high-pressure water jets, and even industrial lasers.

However, many people still prefer the old way of doing things. Artists use hand tools to chisel the blocks of marble, just as they use industrial techniques to carve sculptures. Regardless of the tool used, the process is essentially the same.

Types of stone sculptures

Stones come in many different varieties, giving artists many options in terms of color, quality and hardness. The hardest and most weather-resistant stones are igneous rocks, formed by the cooling of molten rocks such as granite, diorite, and basalt. Sedimentary stones like alabaster (gypsum) can also be used, although they contain distinct formations. Metamorphic stones, formed by changes in igneous and sedimentary rocks caused by extreme temperatures or pressures, are very popular with sculptors: the best examples are the different types of marble.

Generally speaking, the softer the stone, the easier it is to carve. According to the MOHS mineral hardness scale invented by German geologist Karl Friedrich Moss (-), soapstone has a MOHS hardness of about 2 and is one of the easiest stones to work with. Next up is alabaster and the softer serpentine, both with MOHS values around 3. Stones with a value of 4 include limestone and sandstone. Harder stones with a MOHS of 6 include travertine, marble, and onyx, with granite and basalt (both 8) being the most durable but hardest to carve.

Conclusion

In stone sculptures, attention is not only to physical features, but also to the more profound aspects of the rock. Various wall coverings, planters and other designs are expertly carved into the stone, creating works of art that are as beautiful as they are stunning. These stone crafts are very popular and they represent a beautiful part of the beauty and glamour of the world today. Stone sculptures is an ancient and moving applied art, and many aspects of human cultural heritage now exist only through the lens of ancient stones.

For more information, please visit Stone Sculpture Manufacturer.