Lapidary is the art of cutting stones. There are also many other forms of lapidary, not just cutting and polishing stones and gemstones. These include: casting, faceting, carving, jewelry, mosaics (e.g. little slices of opal on potch, obsidian or another black stone and with a clear dome (glass or crystal quartz) on top.
Man has been making jewelry from the time of recorded history. The first of the stones was perhaps amber because it was soft with a warm glow that man found appealing. After learning how to drill holes, man then started using a process called bruting where he would rub one crystal against another,catching the smaller chips and using the chips later for the polishing. The box they caught the chips in was called a bruter’s box. Other forms of bruting were accomplished with stones and boards where they would grind the gems down by hand. Centuries before Christ, the Chinese, Aztecs and Maori were cutting a hard material called jade.
The Egyptians were the first in recorded history to work turquoise and they used the stones for their jewelry and the powder from the polishing was used as eye makeup. The American Indians, Persians and Tibetans used the turquoise extensively in their jewelry. The American Indians also combined fossilized coral and shells in their jewelry.
In the ancient Persia, today we know it as Iran, the art of faceting was discovered during the early Islamic period. They exported their craft to Egypt and other countries of the day. It is their studies of the faceted stone that gave way to the study of light refraction within the stone. The techniques of diamond splitting, done to obtain natural octahedral forms of the crystal, was known in Gaul and Germany. By about 1380, a method of true diamond cutting was practiced in France.
In the 1400′s, the breakthroughs started in earnest. First in importance was the work of Louis de Berquen, of Bruges, Flanders. Generally acknowledged as the Father of Modern Diamond Cutting, he is best known for his introduction, about 1476, of absolute symmetry, improvements in the polishing process, and the development of the pendeloque shape.
He is also credited with the development of the horizontally mounted metal grinding wheel, (known in diamond parlance as a skeif.) It is doubtful if he actually developed the wheel. What he unquestionably did do for the first time, was to cover the metal wheel with diamond dust suspended in oil. The oil, of course, kept the diamond particles on the rotating wheel rather than allow centrifugal force to sling them away. This led to extraordinary advances in polishing technology and control of the cut stones.
Over the next few hundred years, the craft of faceting spread through out Europe. They gradually graduated from using cast iron wheels and discs utilizing hard corundum sand and silicon carbide to using diamond impregnated materials. It has only been in the last century that the faceting has infiltrated into India where they had for a while, unequal facets of stones where they tried to cover poor quality stones. They are getting more and more reliable with their cuts and some of the better stones are starting to be seen coming out of the area.
The term “lapidary” is derived from the word lapidaries, which were medieval ‘treatises’ on alchemy, mineralogy, chemistry and other sciences.
Perhaps the best documentarian on the subject of medieval gem-cutting was Theophilus Presbyter (c.1070 – 1125), a Benedictine monk with a fascination for the applied arts. In Theophilus’ ‘On Divers Arts’ De diversibus artibus (c.1125), his treatises on the polishing of gemstones goes into great detail in describing various techniques. For the polishing of “onyx, beryl, smaragdus (emerald), jasper, chalcedony, and the other precious stones” you would make a very fine powder from “fragments of crystal” or “emery” and then work the stone on a “smooth flat limewood board, wet with saliva.”
Theophilus also describes the method for using a ‘dop stick’ by attaching the gemstone to a “long piece of wood of comparable thickness” using “chaser’s pitch,” then rubbing the stone on a wet “piece of hard sandstone,” and decreasing the grit of the abrasive until the stone “becomes brilliant.” Then, using “tile dust moistened with saliva on a goat skin,” you would rub the stone until it is “completely clear.”
To create intricately carved cabochons, cameos, and intaglios (photo above) out of sapphire, early Roman engravers may have used ‘adamas’ (diamond) fragments as carving tools, given that they are the only material that is harder than corundum.
A cabochon is a gemstone which has been rubbed and polished into a simple rounded shape, as opposed to a facetted cut. Up until the 1400s, gem cutters were constrained to cabochon style cuts and odd asymmetrically faceted cuts due to the limited technology at hand. The resulting shape has a convex top with a flat or concave back. The term cabochon is used to describe any gemstone cut shape that is not faceted.
As time went on, the technology began to work more and more for the lapidary to make it possible for the average rock hound to be able to cut stones. Either through tumbling or through cutting cabochons. Tumbling is just a method of replicating what mother nature does in the stream and river beds. Whereas it might takes decades, if not centuries for a stone to tumble in the waters of the streams and rivers to where their edges are rounded and smooth, we can do it in a matter of weeks with a low tech tumbler. Tumblers can be found almost everywhere, from tool stores like Harbor Freight Tools to Sears/Kmart/Target/Walmart.