Techniques of Granulation
For long time certain antique golden objects covered with tiny gold balls puzzled both goldsmith and scholars. Only in the last few decades have they unraveled the mysteries involved and have thus made it possible both to produce similar pellets and to solder them to surface of larger objects it possible both to produce similar pellets and to solder them to surfaces of larger objects.
The granulation technique was already known in the third millennium BC. The Etruscans perfected it .It is not easy for the layman to grasp how such small pellets of gold could be formed at all. The particles, often no more than a millimeter thick, were made of cuttings of the thinnest gold wire. According to some scholars, to achieve the same results, the Etruscans let molten gold splatter onto a polished stone surface.
The pellets are heated in coal dust to just below their melting point so that surface gold if combines with tiny particles of coal. This makes the pellets melt more easily on the surface than in the center. The result is that they can be welded onto the surface of the objects they are to decorate without losing their shape.
By chance, the Englishman Little dale discovered .a soldering technique in 1933 which might have been employed by the Etruscans. He noticed that cooked fish glue took on copper oxide when reheated. Further experiments led him to suppose that classical granulation methods employed fish glue mixed with copper carbonate to fix the pellets to the surface. When heated, the glue burnt away, leaving the copper which had entered into a barely perceptible union with the old. This fixed the pellets to one another and to the surface.
An historian Hans Muhlestein called granulations technique which has a very ancient history one that takes us to the heart of the ancient Cretan and Aegean culture. True, the later Greeks I at the same time as the Etruscans, created many finer and justifiably renowned geometrical objects But not even those can compare with can work at its best. These Greek objects, like thug A of Cretan and Mycenaean origin, were not produced Pulviscolo the technique which was the particular pride of Etruscan craftsmen.
Pulviscolo granulation was based on the principle of economy. The technique involved sprinkling powder, and a binding agent, on a golden s before heating, some of the powder would be moved to create the impression of decorative silhouettes.
Pure gold has a melting point of 1063 degrees centigrade, a temperature that was in early times held constant with the aid of blowpipes and later with bellows. The ancient Egyptians had already mastered the technique, thus enabling them to cast gold objects. But, unlike working with most other metals, crafts- men handling gold through the ages have tended to prefer “cold" processing techniques.
Basically, there are two forms of casting: sand casting and the so-called lost wax or cireperdue technique. In the former method, a mold is filled with molten gold. If simple shapes are involved, the mold can be reused many times. If the shapes are more complex, the mold generally serves only once. When a wax model is used it is surrounded by a hardened substance; the wax is heated, melts and flows off. The remaining cavity is filled with gold. After A the molten gold has cooled, the mold is broken leaving the gold equivalent of the wax model.
The Old Testament mentions a particular kind gold casting. When Moses was on Mount Sinai, the‘: Israelites prevailed upon Aaron to cast a golden for them and contributed their gold earrings to melt down for the purpose. And he received them and fashioned it with a graving tool, he had made it in molten call (Exodus 32. 4). Or the Biblical rendition, it is unclear whether it was large casting earrings are unlikely to have sufficed
This interpretation appears to be confirmed by a passage describing Moses’ anger at the golden c if and he took the calf which they had made A» burnt it in the fire and ground it to powder strewed it upon the water, and made the children of Israel drink it” (Exodus 32, 20). One can imagine Aaron proceeding as follows: he modeled image of a calf out of clay and covered it with layer of wax into which he worked the finer points of detail. The calf was then covered with a layer of this substance had part of the copper removed from their surfaces through a complicated process. These objects remained harder than gold but retained the glitter of natural gold.
Today, the following alloys are most commonly used green gold derived from gold, nickel, zinc and cadmium; red and yellow gold derived from gold, silver and copper white gold made of gold, nickel, zinc and palladium. All precious metal alloys are supposed to bear the stamp of the goldsmith as well as an indication of gold content.
The gilding process deals with all methods for coating metallic or non-metallic objects with gold. The oldest gilding technique is plating, the application of gold leaf onto an object, generally for decorative purposes. By covering less glamorous materials such as stone and wood with precious metal, they are removed from the realm of the ordinary and given a special luster. Today gold leaf can be rolled out so thinly that when, for example, plaster is being gilded, the labor costs may be higher than the outlay for the gold needed. In modern metal work and jewelry design, plating refers to the process of covering one metal with another, and not exclusively to gold,
In Egypt, stone and wood are known to have been gold plated as early as the third millennium BC. Gilding by means of gold leaf was undertaken during the Fifth Dynasty (2560-2420 BC).
By the time of Ancient Egypt’s Middle Kingdom, gilding by fire was employed. A papyrus from the third century refers to the methods used Gold and lead are rubbed together to form a powder, two parts lead to one part gold. This mixture is soaked in gum Arabic. It is smeared onto the object to be gilded and heated. The process is repeated until the metal has taken on the color of gold.
A variation on the theme of gilding by fire known from Roman times makes use of mercury which amalgamates with gold. A pasty mixture of gold mercury is smeared over the object to be treated the mercury evaporates on being heated while the gold binds itself to the object’s metallic surface.
The Renaissance goldsmith and craftsman Benvenuto Cellin recommended mercury gold ram of eight to one. He said the amalgamation of the metals should take place in a red hot crucible. According to Cellini, the amalgam should be washed out and spread over the object, which should previously have been prepared with wire brush. The gilding is then allowed to “dry” over a weak fire.
Mercury vapors are highly poisonous and a galvanic method has been used exclusively since its invention by Brugnatelli in I805. Galvanizing involves dipping the object in a bath saturated with the metal to be used for the coating, together with a conducting solution. A direct current conducts the gold particles to the surface of the object.
Genuine or Fake
The art of the forger is almost as old as the art of the goldsmith. Forgery encompasses a variety of activities. It includes falsely claiming to use precious metals. It includes imitating the style of master craftsmen or copying their work: It ca h also of late include antiquing objects of art to increase their value.
The earliest known forgeries in which the value of gold was involved concerned the use of substitute metals. This deception led to the development of techniques for determining, beyond a shadow of doubt, the gold content of any object. Thus, Archimedes, in deciphering the mystery of specific gravity, was the to prove that the royal recipient of a gold crown had been
When the market value of an object exceeds its raw material value, imitation can he very profitable. Enea vico took imitators of antique gold coins to task in a book he wrote in 1558. The Renaissance had aroused much interest in numismatics and there was great demand for Greek and Roman coins Forgers in those days already went beyond seeking, to duplicate the appearance of the coins they produced. They went to great pains to provide those coins with suitable credentials having them discovered in ancient graves and urns,
The famous coin cabinet of Due jean de Berry (1340-1410 contained, as is now known, many forgeries of Dutch and French origin. It is possible g that the duke had copies made of specimens that were hard to acquire, to round off his collection. The antiquarian, Giovanni Cavino (1500-1570), and a the architect, painter, scholar dad writer, Pirro Li Gorio (1500-1583), had reputations as particularly sophisticated forgers of coins and, at the same time, n highly expert numismatists.
More difficult than copying coins was imitating a ancient jewelry and precious vessels which were also much sought after darting the Renaissance.. Forgery o of antiques was very much the order of the day. But the relationship between imitation and original work was not as sharply drawn then as it is today. During the late Middle Ages and the Renaissance the distinction between an undisguised effort to copy a beautiful antique object and out-and-out deceitful forgery was not always clear and not always relevant. Benvenuto Cellini often copied and restored antique al works. It is possible to conclude from his autobiography that he was among those who drew no strict distinction between what was purely his own work and what was his imitation of the work of others. It is, therefore, perhaps poetic justice Hun later, particularly in the nineteenth century, various goldsmith their own Work tut hit Marker name to gather the rewards of his reputation
One of the strangest eases in the history of forgery of goldsmith's work was that of the Tiara of saita Themes said to have been the crown of an Etruscan ruler. This splendid object, allegedly present the Scythian king Saitaphrmes, turned op in Vienna in the 1880’s as Offered to WO collectors then fur 100,000 cold. No sale was made, lurk. Ht because the cxceptimally good condition of in item such reported antiquity aroused the suspicious of on expert. But somewhat later, the Paris offered 200,000 gold francs for the crown and the acquisition was authenticated and celebrated in various learned journals by a number of experts.
Not long afterward, however, a French jeweler announced that the crown was indeed a forgery and that he knew who had made it a goldsmith named Ruchomowski from the city of Odessa. Ruchomowski acknowledged the work as his own without further ado and disclosed that it Was a piece which a number of art dealers had commissioned from hint I le said he had produced tin them a whole series of antique pieces which were partly copies of ancient models and partly of his own design. Art historians and archaeologists who had earlier written so enthusiastically of the discovery would, however, only accept that it was a forgery when Ruchomowski created another Etruscan object, in public and without a model to work from.
The Italians Alessandro and Augusto Castelani were also master forgers. They produced excellent Etruscan and Roman gold and silver objects in the early nineteenth century. Their forgeries so closely resembled the originals in styles and techniques that even experts were unable to distinguish them.
The nineteenth century was a hey day for forgers for antiques virtually every European city wanted to have its own art collection in addition an obsession with history had pervaded even the gold smith’s profession many goldsmiths of the period became acquainted with the accomplishment of their predecessor and tried to match their predecessor and tried to match their skills forgers benefited from the fact that basic techniques of gold smithery had hardly varied at all for centuries even millennia.
A forget of medieval paintings is faced with exalt formidable challenges he must capture appropriate colors and acquire the proper brushes surfaces to work with. But the goldsmith of today practically the same materials and tools as his remote predecessors Experts therefore often find hard to detect the forgeries of goldsmiths who well versed in the history of styles.
Authentication of an object requires an absolutely proof account of its origins; but competent for usually manage to manufacture suitable histories go with the objects they have fabricated.
The Ruchomowski case is the story of a chance discovery of an almost perfect forgery. It is, in the last analysis, virtually impossible to say how many other masterpieces will one day prove to have been forgeries
The collector of jewelry is faced today with many more serious problems than his counterpart at the beginning of this century. He is obliged to concentrate on a fairly narrow specialty if he wishes to be systematic in his approach. Those wishing to build collections reflecting the entire spectrum of history would need enormous financial resources as well as considerable grasp of the field. The opportunities for setting up an impressive collection are appreciably greater if the collector is prepared to concentrate on, for example, the Renaissance or Baroque periods. But now that nineteenth century jewelry has gained recognition and respect, that field clearly offers the greatest possibilities. Among the rarest field is rnedieval jewelry. When it comes to the early and high middle Ages, only newly discovered treasure is likely to produce new opportunities. However, collectors may choose to specialize in certain categories. Like devotional jewelry, keepsakes or rings.
Gold was considered the exclusive property of goods and rulers in ancient Egypt it was a sign of omnipotence so treasured that the Egyptians went to war and demanded enormous tribute from the moment that a pharaoh decided that his claim to immortality would be enhanced by the radiance of objects dedicated to his greater glory and glittering brilliantly throughout history lumps of gold drilled through or hammered threaded into a chain pieces of gold woven into hair those must have been among the earliest gold ornaments.
In the Nile delta its probable place of origin the goldsmith art flourished and developed adequate proof is provided by the tomb of Tutankhamen who was pharaoh of Egypt between 1358 and 1350 BC.
The English archaeologists Howard catter and lord Carnarvon began to dig in the valley of the kings in 1907 but not until 1922 did they discover the entrance to the Tutankhamen tomb their burial chamber was opened and the tenacious explorers came upon the richest and most valuable treasure of antiquity.
The tomb relatively modest in proportions was built into the ground and consist of only four chambers itself they found the mummified body of the pharaoh in an anthropoid coffin about seven feet long and made of solid gold the pharaoh’s head was completely enveloped in a portrait mask of solid gold beaten and burnished.
Most of the treasure of Tutankhamen was in the adjoining chambers among its most memorable objects were a pair of statue which portrayed the boy king as guardian of his own tomb and large canopy completely overlaid with gold there were also a golden throne a canopic chest of beaten gold contaminating the viscera of the dead pharaoh and a host of other gold and gilded objects of historic and aesthetic distinction.
The shrine of Anubis in the tomb was particularly notable for the const between the finely structured golden casket and the black lacquered figure of the god in jackal from the back of the throne bore a design based on other no less fascinating theme the golden overly was decorated with small colored inlays of porcelain glass and stone the combination of colors produced a striking effect the creator of the massive golden death mask used color in a more and blue glass resembling lapsi lazuli enshrines the magnificently shaped face like a halo.
Master pieces in museum:
The most important specimens of Egyptian gold smith work are to be found in the curio museum.
The importance of the discovery of the tomb of Tutankhamen in Egypt was equalled by find in the part of the Middle East known as Mesopotamia. During the 1920‘s and 1930’s sir Leonard Woolley excavated the burial grounds of the ancient city of Ur. He comes upon royal graves replete with Buried golden treasure.
Amidst many hundreds of graves whose contents were of comparatively limited enduring value Woolley found sixteen tombs with enormously valuable contents. Two of the most magnificent those of the Kings Meskalamdug and Akalamdugwere recognizable by the presence of royal seals The rulers of Mesopotamia did not venture into the kingdom of the dead accompanied only by symbols of power and the masterpieces of contemporary craftsmen they were also a sent off with servants to pull those chariots must have resembled to a fertility rite rather than merely a royal burinal.
Excavations revealed that Mesopotamian kings the third millennium BC employed goldsmiths when styles had remained unchanged over a long of time and who were particularly skillful at beating and embossing gold. The culture blended a remark measure of splendor and high artistic achievement.
Three of the most impressive finds bear witness to this:
The crown of queen shubad it has been suggested that this was actually a kind of necklace consists of pieces of gold leaf cut into leaf like shapes with increased robes the leaves are attached to three chains of lapis lazuli and red carnelian.
The helmet of Meskalamdug is a unique example of the gold beating what was thought to be a helmet for battle or displays has recently been identified as a wig of beaten gold for use in festivals or ceremonial occasions.
A twenty nine inch high animal image made of wood and probably of religious significance represent still another form of Mesopotamia craftsmanship its head and legs are coated with electrum leaf its belly with silver the pelt is of muscle shells its beared and horn of lapis lazuli.
The quantity of gold objects unearthed is remarkable all the more surprising because there appears to have been no skill at gold working in previous cultures no gold was mined in mesopot5amia itself which may account for the sparing use of the precious metal the people of are believed not have been warriors they used the widespread use of lapis lazuli in Mesopotamia suggests that goldsmiths there acquired much of their raw materials from Egypt.