Lapidary

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Examples of lapidary products Lapidary 3302.jpg
Examples of lapidary products
Gemcutting in Thailand Thai Gem Cutting.jpg
Gemcutting in Thailand

Lapidary (from the Latin lapidarius) is the practice of shaping stone, minerals, or gemstones into decorative items such as cabochons, engraved gems (including cameos), and faceted designs. A person who practices lapidary is known as a lapidarist. A lapidarist uses the lapidary techniques of cutting, grinding, and polishing. [1] [2] [3] Hardstone carving requires specialized carving techniques. [2]

Contents

In modern contexts, a gemcutter is a person who specializes in cutting diamonds, but in older contexts refers to artists who produced hardstone carvings; engraved gems such as jade carvings, a branch of miniature sculpture or ornament in gemstone.

By extension, the term lapidary has sometimes been applied to collectors of and dealers in gems, or to anyone who is knowledgeable in precious stones. [4]

Etymology

A 17th century European lapidary text Titlepage; The Expert Lapidary Wellcome L0064654.jpg
A 17th century European lapidary text

The etymological root of the word 'lapidary' is the Latin word 'lapis', meaning "stone". [5] In the 14th century, the term evolved from 'lapidarius', meaning "stonecutter" or "working with stone", into the Old French word 'lapidaire', meaning "one skilled in working with precious stones". [5]

In French, and later English, the term is also used for a lapidary text, which was a treatise on precious stones that details their appearance, formation, and properties - particularly in terms of the powers believed to be held by some stones - as believed in medieval Europe. The beliefs about the powers of stones included their ability to prevent harm, heal ailments, or offer health benefits. [6] 'Lapidary' appeared as an English adjective in the 18th century. [5]

History

Lapidary tool kit from around 900 AD, Chaco Culture National Historical Park Lapidary tool kit, NPS.jpg
Lapidary tool kit from around 900 AD, Chaco Culture National Historical Park

The earliest known lapidary work likely occurred during the Stone Age. [1] [7] As people created tools from stone, they inevitably realized that some geological materials were harder than others. The next earliest documented examples of what could be considered lapidary arts came in the form of drilling stone and rock. The earliest roots of drilling rocks date back to approximately one million years ago. [8]

The early Egyptians developed cutting and jewelry fashioning methods for lapis lazuli, turquoise, and amethyst. [9]

The art of lapidary was relatively well-developed in the Indian subcontinent by the early 1st millennium CE. The surviving manuscripts of the 3rd century Buddhist text Rathanpariksha by Buddha Bhatta,[ citation needed ] and several Hindu texts of mid-1st millennium CE such as Agni Purana and Agastimata, are Sanskrit treatises on lapidary arts. They discuss sources of gems and diamonds, their origins, qualities, testing, cutting and polishing, and making jewelry from them. [10] [11] [12] Several other Sanskrit texts on gems and lapidary arts have been dated to post-10th century, suggesting a continuous lapidary practice. [13]

According to Jason Hawkes and Stephanie Wynne-Jones, archaeological evidence suggests that trade in lapidary products between Africa and India was established in the 1st millennium CE. People of the Deccan region of India and those near the coast of East Africa had innovated their own techniques for lapidary before the 10th century, as evidenced by excavations and Indian and non-Indian texts dated to that period. [14]

Lapidary was also a significant tradition in early Mesoamerica. The lapidary products were used as status symbols, for offerings, and during burials. They were made from shell, jade, turquoise, and greenstones. Aztec lapidarists used string saws and drills made of reed and bone as their lapidary tools. [15]

Techniques

A jewellery worker in Sri Lanka (2006 photograph) Zafirs-treball2.jpg
A jewellery worker in Sri Lanka (2006 photograph)

There are three broad categories of lapidary arts: tumbling, cabochon cutting, and faceting. Among a modern gemcutter's work are the following activities:

Cutting

Cutting of harder stones is done with a diamond-edged saw. For softer materials, a medium other than diamond can be used, such as silicon carbide, garnet, emery, or corundum. Diamond cutting requires the use of diamond tools because of the extreme hardness of diamonds. The cutting, grinding, and polishing operations are usually lubricated with water, oil, or other liquids. Beyond these broader categories, there are other specialized forms of lapidary techniques, such as casting, carving, jewelry, and mosaics.[ citation needed ]

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 bladed 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. 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.

Faceting

Faceting requires equipment allowing for very precise adjustment of angle and location around the gemstone for facet-placement, a process sometimes referred to as indexing. The design may be computer-generated or left up to the skill and expertise of the individual cutting the gemstone.

During the process of grinding, faceting, and lapping, the gemstone is usually affixed ("dopped") to a rod (frequently referred to as a "dop" or "dopstick") made of wood, or perhaps brass or steel, with dopping cement, a specialized thermal adhesive. The dopstick can be hand-held or inserted into the indexing equipment for more precise faceting. A coolant then needs to be constantly applied to prevent softening of the cement. Diamonds, however, are held mechanically, or with low-melting point tin-lead solder, since the resultant heat generated by friction can be extreme, thus preventing the use of thermal adhesives.

Cabochons - smooth-shaped gemstones without facets such as jade or turquoise, and indeed most gemstones - are instead shaped and polished in much the same manner. They are usually left up to the skill and expertise of the individual cutting the gemstone and to similar equipment such as the lapping equipment.

Polishing

Most modern lapidary work is done using motorized equipment. Polishing is done with resin- or metal-bonded emery, silicon carbide (carborundum), aluminium oxide (corundum), or diamond dust in successively decreasing particle sizes until a polish is achieved. In older systems, the grinding and polishing powders were applied separately to the grinding or buffing wheel. Often, the final polish will use a different medium such as tin oxide or cerium(IV) oxide.

The initial shaping and facet placement may be done using laps with grits of 220, 600, 1200. The polishing step, however, requires grits of a much higher grade, such as 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.

Inlaying

Another specialized form of lapidary work is the inlaying of marble and gemstones into a marble matrix. This technique is known in English as pietra dura , for the hardstones that are used, like onyx, jasper and carnelian. In Florence and Naples, where the technique was developed in the 16th century, it is called opere di commessi. The Medici Chapel at San Lorenzo in Florence is completely veneered with inlaid hard stones. The specialty of micromosaics , which developed in the late-18th century in Naples and Rome, is sometimes covered under the umbrella term of lapidary work. In this technique, minute slivers of glass are assembled to create still life, cityscape views, and other images. In China, lapidary work specializing in jade carving has been continuous since at least the Shang dynasty.[ citation needed ]

Societies and clubs

There are lapidary clubs throughout the world. In Australia, there are numerous gem shows, including an annual gem show called the GEMBOREE, which is a nationwide lapidary competition. There is a collection of gem and mineral shows held in Tucson, Arizona, at the beginning of February each year. The event began with the Tucson Gem and Mineral Society Show and has now grown to include dozens of other independent shows. In 2012, this concurrent group of shows constituted the largest gem and mineral event in the world. [ citation needed ]

See also

Related Research Articles

Gemstone Piece of mineral crystal used to make jewelry

A gemstone is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks and occasionally organic materials that are not minerals are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gemstone.

Topaz Silicate mineral

Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F, OH)2. It is used as a gemstone in jewelry and other adornments. Topaz in its natural state is a golden brown to yellow. A variety of impurities and treatments may make topaz wine red, pale gray, reddish-orange, pale green, pink, or opaque.

Ruby Variety of corundum, mineral, gemstone

A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum. Other varieties of gem-quality corundum are called sapphires. Ruby is one of the traditional cardinal gems, together with amethyst, sapphire, emerald, and diamond. The word ruby comes from ruber, Latin for red. The color of a ruby is due to the element chromium.

Diamond cutting

Diamond cutting is the practice of shaping a diamond from a rough stone into a faceted gem. Cutting diamond requires specialized knowledge, tools, equipment, and techniques because of its extreme difficulty.

Cabochon

A cabochon is a gemstone which has been shaped and polished as opposed to faceted. The resulting form is usually a convex (rounded) obverse with a flat reverse. Cabochon was the default method of preparing gemstones before gemstone cutting was developed.

An abrasive is a material, often a mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away by friction. While finishing a material often means polishing it to gain a smooth, reflective surface, the process can also involve roughening as in satin, matte or beaded finishes. In short, the ceramics which are used to cut, grind and polish other softer materials are known as abrasives.

Facet

Facets are flat faces on geometric shapes. The organization of naturally occurring facets was key to early developments in crystallography, since they reflect the underlying symmetry of the crystal structure. Gemstones commonly have facets cut into them in order to improve their appearance by allowing them to reflect light.

Diamond cut Style or design guide

A diamond cut is a style or design guide used when shaping a diamond for polishing such as the brilliant cut. Cut does not refer to shape, but the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond's brilliance; this means if it is cut poorly, it will be less luminous.

Sharpening stone Abrasive slab used to sharpen tools

Sharpening stones, or whetstones, are used to sharpen the edges of steel tools and implements, such as knives, scissors, scythes, razors, chisels, hand scrapers, and plane blades, through grinding and honing.

Lake Superior agate

The Lake Superior agate is a type of agate stained by iron and found on the shores of Lake Superior. Its wide distribution and iron-rich bands of color reflect the gemstone's geologic history in Minnesota, Wisconsin, Nebraska, Iowa, Kansas and Michigan. In 1969 the Lake Superior agate was designated by the Minnesota Legislature as the official state gemstone.

When a gemstone is desired to be used in jewelry, it is cut depending on the size and shape of the rough stone, as well as the desired piece of jewelry to be made. As a general rule, a cut gemstone will reduce the mass by about 50 percent.

Diamond tool

A diamond tool is a cutting tool with diamond grains fixed on the functional parts of the tool via a bonding material or another method. As diamond is a superhard material, diamond tools have many advantages as compared with tools made with common abrasives such as corundum and silicon carbide.

Stonesetting is the art of securely setting or attaching gemstones into jewelry.

A 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 machines is found between those that facet diamonds and those that do not. Specialized equipment is required for diamond faceting, and faceting as an occupation rarely bridges the gap between diamond and non-diamond workmanship. A second division can be made between industrial faceting and custom/hobby faceting. The vast majority of jewelry-store gemstones are faceted either abroad in factories or entirely by machines. Custom jewelry is still commonly made of custom metalwork and mass-produced gemstones, but unusual cuts or particularly valuable gemstone material will likely be faceted on a personal faceting machine.

Lapidary clubs promote popular interest and education in lapidary, the craft of working, forming and finishing stone, minerals and gemstones. These clubs sponsor and provide means for their members to engage in all forms of jewellery making, cabochon cutting and faceting, carving, glass beadmaking and craft work. The clubs also promote and facilitate healthy outdoor activities in the form of field trips to various fossicking locations for the purpose of collecting gemstones or mineral specimens. Lapidary is particularly popular in the United States of America and Australia where large numbers of clubs were formed in the 1950s and 1960s.

Bezel (jewellery)

The bezel is a wider, and usually thicker, section of the hoop of a ring, which may contain a flat surface, or a gem. The ring is normally worn to display the bezel on the upper or outer side of the finger. The word may also refer to a bezel setting for a stone, which is a general term for a setting holding the stone in place using a raised surrounding for the stone with a lip encircling and overlapping the edges of the stone, thus holding it in place. Modern bezel settings typically use a band of metal containing a groove and a flange to hold a watch crystal or gemstone in its setting. This was the earliest method of setting gemstones into jewelry. In historic examples, such rings were often made by leaving a hole or slot in the ring with a thin lip which was bent over once the stone was inserted, holding it in place.

Diamond (gemstone) Gemstone

Diamond is one of the best-known and most sought-after gemstones. They have been used as decorative items since ancient times.

Hardstone carving Artistic carving of semi-precious stones or gems

Hardstone carving is a general term in art history and archaeology for the artistic carving of predominantly semi-precious stones, such as jade, rock crystal, agate, onyx, jasper, serpentinite, or carnelian, and for an object made in this way. Normally the objects are small, and the category overlaps with both jewellery and sculpture. Hardstone carving is sometimes referred to by the Italian term pietre dure; however, pietra dura is the common term used for stone inlay work, which causes some confusion.

Shelby Gem Factory American artificial gemstone manufacturer

The Shelby Gem Factory, also known as ICT Incorporated, was a Michigan company that manufactured artificial gemstones through proprietary processes. The factory made more varieties of man-made gemstones than any other in the world. It grew artificial gems and gem simulants, including synthetic ruby and sapphire and simulated diamonds, citrine, topaz, and other birthstone substitutes, and mounted them in gold or silver jewelry.

Dopping cement, dopping wax, or faceting wax is a thermal adhesive used by gem cutters to secure ("dop") a gemstone to a wooden or metal holder for grinding and lapping. Setters cement is a similar material used to secure a gemstone while setting or polishing.

References

  1. 1 2 Ripley, George; Dana, Charles A., eds. (1860). "Lapidary". The New American Cyclopædia. Volume X, Jerusalem–MacFerrin. New York: Appleton. pp. 310–311.|volume= has extra text (help)
  2. 1 2 Kraus, Pansy D. (1987). "Preface". Introduction To Lapidary . Iola, Wisconsin: Krause Publications. p. ix. ISBN   978-0-8019-7266-9.
  3. "Oxford Dictionaries: Definition of lapidary in English". Oxford University Press. Archived from the original on 22 September 2012.
  4. "lapidary". Webster's New World College Dictionary, 4th Ed. Archived from the original on 3 May 2007.
  5. 1 2 3 Douglas Harper (2014), Lapidary, Online Etymology Dictionary
  6. William W. Kibler (1995). Medieval France: An Encyclopedia. Routledge. pp. 990–991. ISBN   978-0-8240-4444-2.
  7. Cocca, Enzo; Mutri, Guiseppina (2013). "The lithic assemblages: production, use and discard". In Garcea, Elena A. A. (ed.). Gobero: The No-Return Frontier Archaeology and Landscape at the Sahara-Sahelian Borderland. Journal of African Archaeology Monograph Series 9. Frankfurt am Main, Germany: Africa Magna Verlag. pp. 129–166. ISBN   978-3-937248-34-9.
  8. The full and complete history of the lapidary arts International Gem Society, Retrieved January 7, 2015
  9. Kraus, Pansy D. (1987). "History of Lapidary". Introduction To Lapidary . Iola, Wisconsin: Krause Publications. p.  1. ISBN   978-0-8019-7266-9.
  10. Sures Chandra Banerji (1989). A Companion to Sanskrit Literature. Motilal Banarsidass. p. 121. ISBN   978-81-208-0063-2.
  11. Mohsen Manutchehr-Danai (2009). Dictionary of Gems and Gemology . Berlin: Springer. p.  10. ISBN   978-3-540-72795-8.
  12. Louis Finot (1896). Les lapidaires indiens (in Sanskrit and French). Champion. pp.  77–139, see other chapters as well.
  13. Louis Finot (1896). Les lapidaires indiens (in Sanskrit and French). Champion. pp. xiv–xv with footnotes.
  14. Jason D. Hawkes and Stephanie Wynne-Jones (2015), India in Africa: Trade goods and connections of the late first millennium, L’Afrique Orientale et l’océan Indien: connexions, réseaux d'échanges et globalization, Journal: Afriques, Volume 6 (June 2015), Quote: " The Periplus of the Erythraean Sea, and the Sanskrit Mricchakatika both refer to the jewels made in Ujjain. The evidence from excavations at Ujjain itself, as well as that from surrounding villages, supports this identification. These workshops fed the main market for international trade at the city port of Baruch, at the mouth of the Narmada, which has long been recognized as the main coastal port of the early first millennium. At some point in the mid to late first millennium AD, the center of lapidary workshops appears to have moved from Ujjain to Limudra, and the main port shifted to Khambhat. Exactly when this shift took place and why it occurred is unclear. What is interesting, however, is that throughout the first millennium AD there was a clear and close spatial association between 1) source areas, 2) production centers, and 3) ports connected to the Indian Ocean."
  15. Susan Toby Evans; David L. Webster (2013). Archaeology of Ancient Mexico and Central America: An Encyclopedia. Taylor & Francis. p. 400. ISBN   978-1-136-80185-3.