This week I’m featuring two guest blog posts by my main gemstone supplier, George Ingraham of TaoGem. The first post gave some information on what lapidary is, and in this post he talks about the history of lapidary work.
Lapidary History / Early Gemstone Cuts
The Bead was probably the first gemstone cut used by man, dating back several thousand years. Limited by the tools available at the time, as well as the hardness of most gemstones, the simple bead or ‘cabochon’ were the logical choice for jewelry making and ornamentation. Stones where shaped by rubbing them with other stones, then polished using ‘sand’ as an abrasive.
Intricately carved cabochon cuts known as ‘Glyptic’ gem carvings, date back to the 7th millennium BC, and were popularized throughout ancient Egypt (scarabs), Indus Valley, and China (carved jade).
Engraved ‘Glyptic’ gems were used as personal signets or seal-stones which could be impressed into wax or clay to create a signature. The examples above are of early Roman gemstone cuts using the pre-renaissance cabochon cut with several variations of cameo and intaglio styles.
Medieval Lapidary Techniques
A “lapidary” (edelsteinschneider) is an artisan who works with stone, minerals, or gemstones, forming them into decorative or functional objects. 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.