There seems to be a problem serving the request at this time. Have you ever marveled at the engravings on cameos or the faceting of diamonds and gemstones? Maybe you have wondered who makes them and how it is accomplished. These designs are constructed through the use of lapidary equipment. Many lapidaries are certified gemologists, and all of them are considered to be jewelers. Lapidary equipment includes tools such as sanders, drills, arbors, files, and grinders.
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A stone may have fallen into a fire where the heat caused it to break or flake. Perhaps a sharp edge resulted. Certainly, flint and other hard stone possess sharp edges, but a blade-like cutting edge on a newly flaked piece of rock suggested some very interesting possibilities. He scratched and chiseled out symbols and primitive writings on hard rock and cave walls — and gradually learned the great secret: some stones are harder than others and therefore they are more capable of inflicting scratches on other less hard stones.
Primitive peoples learned that rocks could be broken or fractured. The breakage provided random fragments, but ultimately experimentation demonstrated that breakage could also be achieved with some semblance of control. The slow and tedious practice of bruting was used for centuries until more refined techniques were introduced. It was satisfactory that the breaking, chipping, or flaking of a stone could be disciplined…made to occur in desired directions and depth.
No doubt, too, man compared the smooth, river and stream rolled stones with those found elsewhere. Even here, it required no great stretch of thinking to conclude that something was exerting a smoothing or polishing effect on certain stones.
Could it be other mineral particles in the river working to complement the action of the constantly running water? From such questions, the advance to a rubbing paste of water and sand was virtually inevitable.
Whether many of these later discoveries broke in the Paleo or Neolithic, early or late Stone Age, is of little consequence. What is known is that man used the new found phenomena in anticipation of the many tools and pieces of equipment of succeeding years. By 3, B. The Scanning Electron Microscope has analyzed many seals of the early Bronze Age that were uncovered in ancient Mesopotamia.
Showing remarkable skill and tool control by the gemcutters, these seals were often shaped to form a flat or convex seal face with a raised perforated handle on the back. Highly valued, the seals were worn as amulets that could be removed quickly and pressed into a clay tablet.
They were the mark of early man as each seal was an individual creation, made exclusively for its owner.
The existence of these ancient artifacts proves how old the art of lapidary is. The artifacts demonstrate that lapidaries had conquered the challenges of sawing, chipping, drilling, polishing and faceting before the time of Christ. The work was rudimentary by todays standards but the principals upon which this work was performed are still with us. The use of jade and jade look-alikes were prevalent. Materials like serpentine only look like jade, but the real value lies in the lapidary skill lavished on the original rough.
Centuries before Christ, the Chinese knew how to work the tough green material they called yu and which we call jade. The tribes of the Swiss Lake District also worked jade. To be sure, pre-Columbian beads of Mexico and South America were crudely worked samples of jade, but some of the more advanced cultures of ancient Mexico worked the material into incredibly intricate and complex carvings.
Where available, other forms of jade were also used extensively. These other similar appearing by non-jade types included serpentine, prehnite, and aventurine. Naturally, the various kinds of quartz found quick favor among stone workers. They represented an explosion of varied, rich colors and, although their hardness made them a more difficult to work than the softer stones, many different cultures sought them not for their lush cosmetic values but for mystic purposes as well.
The faceted gems of today are incredible optical performers. It has always been that way. For example, the marvelous translucency and transparency of the crystalline quartzes ranged from carnelian , sardonyx, agate , amethyst to rock crystal. The early Chinese, Japanese, Grecian, and Mycenaean peoples found quartz a marvelous mineral for gemcutting, as did the craftsmen of India and Scotland.
Amber is undoubtedly one of the earliest stones to be used in jewelry. It is lightweight, easily drilled, and features a pleasing warm color. It was also found floating in numerous parts of the world in fairly large pieces. Such folk work comes from the Orient, Morocco, Afghanistan, and, of course, the Baltic countries.
Used mostly in necklaces, many of the beads are large, hand-shaped spheres or ovals. Turquoise has a long history in jewelry. The Egyptians of the earliest dynasties focused great attention on this sky-blue stone, often grinding lit into a powder form to provide a unique blue eye shadowing.
It was a highly prized gem of the Mexican cultures, and the Persians and Tibetans used turquoise extensively. Some Germanic people used it as a betrothal stone. Among the American Indians, it was the principal stone. In almost all instances, the workings were those of cabochon cutters, carvers and sculptors who specialized in representational art.
A relatively soft stone, turquoise was easily worked and could quickly be buffed to a nice polished finish with a mixture of sand and water. Sometimes it was worked in a nugget form and other times it was shaped. Used alone or in combination with shell, coral and other soft materials, turquoise has continued in great popularity even up to contemporary times.
Coral, incidentally, is usually vivid in color and easy to shape so it naturally became famous in Tibet, China, India, northern Africa, and the American Indians. Other stones that found early use among gemcutters were meerschaum, jet and lignite, soapstone, lapis lazuli, and malachite.
Where volcanic action was evident, obsidian was also used. It is a medium soft stone, but gemcutters quickly found that quartz pieces and flint could be used to shape it. As a matter of fact, in 5, B. Not so surprising is the fact that the initial use of glass was to serve as an imitation gemstone.
It is pretty much established now that the real discovery of this glazed terra cotta ceramic ware, with its colored decorations, took place farther East and was brought to Egypt by Sumerian merchants.
Factories there were producing a variety of beads made from siliceous stones that are even today marketed all over the world. Artisans of the Bronze and Classical Age, especially those who carved Greek seal stones, used techniques that were enormously time consuming.
It was their habit to cut small chunks from large local blocks. Obsidian served as the sawing agent, the chunks were shaped with Naxian emery, and then apparently given a final polish with other corundum powders made into a watery paste. Indian literature dated about B. Because mani is a term to describe a sphere or bead it appears that some form of gem cutting was practiced that early. Bapu Majajan, a contemporary Indian gemologist and Fellow of the Gemmological Association of Great Britain, feels that these and later references, about B.
It goes without saying that the more famous transparent gems, ruby , sapphire , spinel , emerald and garnet , appeared in many different forms; all the work of advanced gemcutters. Rubies , because they were treasured above all other gems, have been found mounted in their natural shape while others have been faceted and cut cabochon. It is not well known, but many of the advances in faceting can be attributed to the Islamic Period.
In what is now eastern Iran, gemcutters had developed great skills in polyhedral faceting, 11th c. Nishapur, as well as exporting cutting skills which produced such great traditions as the rock formed crystals of Fatima, Egypt c.
Keep in mind that a number of technological developments were necessary before a breakthrough in diamond cutting became possible. There existed, too, a decided shortage of cutting equipment save a few hand tools. Lapidaries much preferred the stones softer then diamond, including ruby, sapphire, quartz, and emerald. The practice of cutting gemstones to a specific configuration along with the refinements of development of diamond-cutting techniques, were established in Europe.
The techniques of diamond splitting, done to obtain natural octahedral forms of the crystal, was known in Gaul and Germany. By about , a method of true diamond cutting was practiced in France. The diamond point is simply the eight natural facets of the crystal. Diamonds occur naturally in this habit, or a bit of judicious splitting, or cleaving, will easily achieve the same thing. One of the problems with these early diamonds was that the unmodified bottom, called the pavilion, was deep.
In the latter half of the 16th Century, the only regular forms of cut diamonds were the so-called diamond point and diamond table, both shapes being based on the octahedron. For the most part, these were small stones used as accents to complement large, colored, cabochon-cut stones. The diamond table cut would not have been all that difficult for the ancients to figure out. On an octahedron, the apex represents a four-point cutting orientation so no matter which way the octahedron was pointed, diamond grit would have successfully ground away the tip to a rude table facet.
In the earlies stages, the method of grinding was simply to rub one crystal face against the other, a process called bruting. Indeed, many diamond cutters of the time had a small box beneath their manipulations. This dust was then used in the polishing process, its grit being so tiny as to effectively remove the larger scratches. The diamond table was produced by grinding across one of the pyramidal apexes of the octahedron.
The facet thus formed was usually about half the width of the central square section. Inspection of old diamond table cuts shows that the cutters brought the table in as square as possible with just a table cut. Occasionally, the sides of the crown were slightly modified to improve the right angles to one another.
Often as not, the cutter would also cut a small flat on the bottom, called the culet. Generally, this was intended to avoid accidental chipping or breakage, which might catch a cleavage plane and extend it deeper into the stone. The cleavage plane on a diamond runs parallel to the octahedral faces so a long split up the entire length of the pavilion was not a minor possibility. For that reason, the practice of cutting a tiny flat culet on the pavilion tip is still practiced today.
The practice is also followed with colored stones. In the latter case, it is not the cleavage that is potentially troublesome.
It is the fragility of a sharp tip on a gemstone that is considerably softer and less accommodating to shock than is diamond. Despite small advancements in cutting styles, the point cut style apparently persisted well into the 17th Century.
The search for visual performance continued. It appears that most of the new innovations were intended to improve surface performance, the scintillation or twinkle caused by reflections, rather than any knowledge application or pursuit of optical advancement.
Doubtlessly, this search led to the development of the single cut.
Catalog Record: Gem cutting : a lapidary's manual | HathiTrust Digital Library
The History of Lapidary