Gemcutter
Encyclopedia
A gemcutter, is a person who cuts, shapes, and polishes natural and synthetic gemstone
s. In historical use it usually refers to an artist who made hardstone carvings or engraved gems, a branch of miniature sculpture
or ornament in gemstone.
Among a modern gemcutter's work are the following activities:
faceted gemstones.
While the gemstone in the rough state may be trimmed to remove undesirable material or to separate it on a cleavage line with a diamond blade
d saw, accurately described as cutting and once done by the use of a chisel
or similar tool to simply break off pieces that were usable as single gemstones.
The actual shaping and polishing of a gemstone is a grinding or sanding process. This grinding and sanding is done using a lap
, a precision metal plate embedded with grit similar to the more familiar embedding of grit on paper the lap is of high precision particularly for flatness and turned by a motor. (See faceting equipment)
The grit material is normally diamond and sometimes corundum for their hardness. Only diamond is hard enough on the Mohs scale to shape and polish a diamond.
The initial shaping and facet placement may be done using laps with the more familiar grits of 220, 600, 1200. The polishing step, however, requires grits that are less familiar 8,000 14,000 50,000 and even 100,000. This grit is also embedded into a metal lap, but sometimes applied manually to the lap during polishing.
With the exception of diamonds a coolant
is constantly applied to keep the gemstone cool since it is usually held in place on the end of a dop using high temperature shellac based wax, paint or other adhesive. (The dop in this case is a machined brass or stainless steel rod)
Diamonds are held mechanically since the heat generated by friction can be extreme and will not allow the use of adhesives.
Cabochon
s, smooth shaped gemstones without facets such as jade
or turquoise
and most gemstones, are shaped and polished in much the same manner, but are usually done by hand relying on the skill of the individual and the use of equipment similar to that shown as lapping equipment
Gemstone
A gemstone or gem is a piece of mineral, which, in cut and polished form, is used to make jewelry or other adornments...
s. In historical use it usually refers to an artist who made hardstone carvings or engraved gems, a branch of miniature sculpture
Sculpture
Sculpture is three-dimensional artwork created by shaping or combining hard materials—typically stone such as marble—or metal, glass, or wood. Softer materials can also be used, such as clay, textiles, plastics, polymers and softer metals...
or ornament in gemstone.
Among a modern gemcutter's work are the following activities:
- Positioning rough stone in a holder, and holding the stone against the edge of a revolving saw or lapidaryLapidaryA lapidary is an artist or artisan who forms stone, mineral, gemstones, and other suitably durable materials into decorative items such as engraved gems, including cameos, or cabochons, and faceted designs...
slitter impregnated with diamondDiamondIn mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...
dust to cut and slit stone. - Removing cut stone and placing it in lapidary stick. A gemcutter then selects the shaping wheel and applies abrasive compound. They hold a lapidary stick against the revolving shaping wheel and lapidary disk to further shape stone and grind facets.
- Examining stone for accuracy of cut, using a magnifying glass. A gemcutter polishes stone, using felt or canvas-covered polishing wheel, and polishing compounds, such as tripoliRotten stoneRotten stone, sometimes spelled as rottenstone, also known as tripoli, is fine powdered rock used as a polishing abrasive in woodworking. It is usually weathered limestone mixed with diatomaceous, amorphous, or crystalline silica...
or rougeRougeRouge may refer to:*Rouge , a cosmetic used to color the cheeks and emphasize the cheekbones*Rouge , a 1987 Hong Kong film*Rouge , an online film journal...
. - Possibly using a mechanical facet-cutting deviceFaceting machineA faceting machine is broadly defined as any device that allows the user to place and polish facets onto a mineral specimen. Machines can range in sophistication from primitive jamb-peg machines to highly refined, and highly expensive, commercially available machines. A major division among...
. A gemcutter may cut and polish diamonds for industrial purposes, and be designated as an Industrial-Diamond Polisher (jewelryJewelleryJewellery or jewelry is a form of personal adornment, such as brooches, rings, necklaces, earrings, and bracelets.With some exceptions, such as medical alert bracelets or military dog tags, jewellery normally differs from other items of personal adornment in that it has no other purpose than to...
-silver.).
Gemcutting
The term gemcutting is used to describe the process of shaping and polishingPolishing
Polishing is the process of creating a smooth and shiny surface by rubbing it or using a chemical action, leaving a surface with a significant specular reflection In some materials polishing is also able to reduce diffuse reflection to...
faceted gemstones.
While the gemstone in the rough state may be trimmed to remove undesirable material or to separate it on a cleavage line with a diamond blade
Diamond Blade
A diamond blade is a saw blade which has diamonds fixed on the blade's base to use the diamonds to cut hard or abrasive materials. There are many types of diamond blades, and they have been applied in many industries, for example, construction industry to cut stone, concrete, asphalt, bricks, coal...
d saw, accurately described as cutting and once done by the use of a chisel
Chisel
A chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.In use, the chisel is forced into the material...
or similar tool to simply break off pieces that were usable as single gemstones.
The actual shaping and polishing of a gemstone is a grinding or sanding process. This grinding and sanding is done using a lap
Lapping
Lapping is a machining operation, in which two surfaces are rubbed together with an abrasive between them, by hand movement or by way of a machine.This can take two forms...
, a precision metal plate embedded with grit similar to the more familiar embedding of grit on paper the lap is of high precision particularly for flatness and turned by a motor. (See faceting equipment)
The grit material is normally diamond and sometimes corundum for their hardness. Only diamond is hard enough on the Mohs scale to shape and polish a diamond.
The initial shaping and facet placement may be done using laps with the more familiar grits of 220, 600, 1200. The polishing step, however, requires grits that are less familiar 8,000 14,000 50,000 and even 100,000. This grit is also embedded into a metal lap, but sometimes applied manually to the lap during polishing.
Faceting equipment
The faceting equipment allows for very precise adjustment of angle and location of facet placement around the gemstone referred to as indexing. The facet design may be computer generated or left to the skill and experience of the individual cutting the gemstone.With the exception of diamonds a coolant
Coolant
A coolant is a fluid which flows through a device to prevent its overheating, transferring the heat produced by the device to other devices that use or dissipate it. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, and chemically inert, neither causing nor...
is constantly applied to keep the gemstone cool since it is usually held in place on the end of a dop using high temperature shellac based wax, paint or other adhesive. (The dop in this case is a machined brass or stainless steel rod)
Diamonds are held mechanically since the heat generated by friction can be extreme and will not allow the use of adhesives.
Cabochon
Cabochon
A cabochon , from the Middle French caboche , is a gemstone which has been shaped and polished as opposed to faceted. The resulting form is usually a convex top with a flat bottom. Cutting en cabochon is usually applied to opaque gems, while faceting is usually applied to transparent stones...
s, smooth shaped gemstones without facets such as jade
Jade
Jade is an ornamental stone.The term jade is applied to two different metamorphic rocks that are made up of different silicate minerals:...
or turquoise
Turquoise
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl648·4. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue...
and most gemstones, are shaped and polished in much the same manner, but are usually done by hand relying on the skill of the individual and the use of equipment similar to that shown as lapping equipment