Jasper is a kind of gemstone or quartz that, unlike other types of quartz, has minute quartz crystals joined and layered together. The gem contains mineral oxides and organic materials that give it attractive patterns, colors, stripes and bands. For instance, jasper comes in a variety of colors, including yellow, red, green and sometimes blue. The stone breaks with a smooth surface, making carving it easy using gem-cutting methods.
Hand carving is a technique of working a gemstone mounted on a metal stick, known as a dop stick, by means of hand-held cutting tools such as a chisel in one hand and a mallet in the other. The result is production of gemstones sculptures, figurines or ornaments. It is a popular technique for carving quartz gemstones such as jasper as well as jade and agate. The gem cutter begins by drawing designs on jasper using rifflers – files with carved edges. The design is cut out using hand carving tools, including a carving knife, coping saw, gouge or chisel. The finished work is sanded with a fine sand paper such as 200-grit diamond-ingrained sandpaper until a glossy finish is achieved.
Lapidary, or gem-cutting, equipment carves gemstones by use of high-powered machinery fitted with silicon carbide blades or a coarse diamond that can cut and shape hard gemstone crystal. The technique is appropriate for quartz gems such as jasper. The gemstone is attached to a dop stick with epoxy, adhesive wax or cyanoacrylate glue. The stick is inserted into a device called a handpiece that enables precise control of gemstone positions. The device sets the stone at angles that allow it to be carved by the silicon carbide blades to desired patterns. The stone is faceted, or ground, sanded and polished, in the final step.
Etching is a craft applied to design patterns on facet stones. Jasper often is carved into designs using this method. Once jasper has been faceted using lapidary equipment, olive oil and compounds of abrasive powders such as diamond dust are rubbed on its flat surface to grind away the designs. Lasers for etching gemstone can be used in place of abrasive powders.
Sawing involves carving or shaping a gemstone using a trim saw, typically 4 to 10 inches in diameter. The technique involves using a thin blade usually made of steel, copper or phosphor bronze alloy hardened along the outer edge with diamond grit. The technique is suitable for carving out designs on jasper, given its quartz and opaque features. The gem is clamped to a vise and cut with a saw. The teeth of the saw are rotated at several thousand surface feet per minute, thus scratching away through the gemstone to achieve the required design. Olive oil or water is used to wash away debris, keeping the saw blade and stone from overheating.