Golden Stories
Gold seduces. Alone already by the irresistible beauty of its shine. And of course through its value and valence, captured in precious pieces of jewelry. Let us delve deeper into its fascinating secret.
Goldsmith’s art
Gold jewelry has a long tradition. As the first gold was found in Egypt in the 5th millennium BC, experts also date the oldest finds of goldsmith’s art objects back to the Chalcolithic period, whereby the burial ground of Varna in today’s Hungary is one of the most important sites. Most of the gold objects found come from the Bronze Age, which is why it is also called the ‘Golden Age’.
Around three quarters of the gold available worldwide today is used to make jewelry.
Gold mining, extraction and refining
The history of goldsmithing as gold jewelry is understandably closely linked to the history of gold mining. Only the finding and extracting-how of that metal allowed its processing into jewelry and the genesis of this artistic handicraft.
When lecturing about gold mining, in general, a distinction is made between mountain gold and soap gold.
Mountain or ‘primary gold‘ is located in quartz veins which are referred to as primary desposits: Mountain gold is formed hydrothermally – liquids containing This usually happens in vein-shaped areas, in this case, as said, in quartz veins. There is evidence that the oldest gold mine is located near the Georgian town of Saktrissi from the period of 3000 BC, around 500 years older than the mainly as oldest known Egyptian mine, located on the upper reaches of the Nile. In Arabia gold was almost certainly mined as early as the 10th century BC; its heyday the country experienced in the Middle Ages. And yet large-scale mining of gold only began in the early modern period, in Chile, Brazil, California and Australia. Finally, around 1850, California experienced the great gold rush, which even began shortly afterwards in Australia. In international comparison, in this field, Europe has always been of little importance, nevertheless, gold is mined in the most European countries, albeit only in small quantities; the Transylvanian Ore Mountains, located in Romania, represent Europe’s important gold mining area. Today, the world’s largest mining of gold takes place in South Africa and China.
Soap gold, also known as washing gold, reaches the earth’s surface over millions of years, like through erosion and weather influences. Gold dust and grains are deposited in rivers, so referred to as secondary deposits and ‘secondary gold‘. This first gold ever was found in Egypt in the 5th millenium BC. Using the so-called gold washing method, the metal is picked out of the river by panning, the oldest method of gold extraction. The placer gold is separated from rock and materials using running water. Flow channels and gutters are the most efficient; depending on the strength of the flow, the materials are deposited and displaced according to their density. It is very likely that the Egyptians built the first gold panning facility around 4000 BC although this can only be used as an assumption as from this period only few written records exist.
Nowadays, the anode sludge process is the most commonly used method of (mountain) gold extraction because, unlike the amalgam process and cyanide leaching, it is more environmentally friendly and effective. This process offers the possibility of obtaining particularly pure gold. Electrolysis is used for this. Here, by supplying strong electrical energy, the metal moves from one electrode to the other and is thus separated from other metals.
Using molds, the liquid gold is then transformed into solid bars, so-called doré bars of low purity which are shipped to refineries for further processing. The final stage – refining – removes impurities that remain after the smelting process. The doré bars are liquified in a furnace. By adding borax and soda ash to the molten metal, the pure gold is separated from other precious and less precious metals.
The value of gold
The element gold is unique because of its resistance to acids, alkalis, corrosion and other environmental influences and conditions. However, one disadvantage is its low harness, it is too easily deformed and damaged, and pure gold is therefore rarely used in jewelry processing. The solution lies in the mixing or ‘alloying’ of gold with other metals (further below) necessary to deliver the strength needed and required for jewelry creations. In the alloying process gold as well as other metals are melted and then mixed in a certain ratio. The purity of gold thus consequently decreases.
The value of gold is indicated by the number of so-called carats. The term carat indicates the fineness of gold, means how large the proportion by weight of pure gold is in the total mass of a gold alloy. The more carats your jewel piece has, the purer it is and the more valuable. 24 carats represents the highest purity possible because it stands for 100% ‘pure’ gold. The most common indications on the market are 18 and 14 carats. Jewelry of 18 carat is of 75 % fine gold and of 25 % added metals, a piece of 14 carats contains a ratio of 58,5% pure gold and 41,5% other metals.
The ‘hallmark’ – a type of embossing that is stamped into the material – tells you how high the gold content of a jewelry item is. This stamp shows the mentioned carat number or a a three-digit numerical value. The three-digit number names the percentage of gold per thousand. A 18 carats gold jewelry is marked as 750 gold, a 14 carats one as 585 gold.
Handicraft manufacturing techniques of gold jewelry
Although jewelers and goldsmiths now have access to modern machines and techniques such as 3D, the true creation and production of high-quality gold jewelry is still characterized by a high amount of manual work.
After gold has been fused with other metals, the still liquid alloy is poured into plates, which are then rolled into sheets or wires. Or the liquid metal is poured into water through a heat-resistant sieve to make gold granules; the metal drips through the sieve, forming quite round balls in free fall.
Taking the construction of rings: The basic ring shape is either punched out of a plate which offers the advantage of creating an uninterrupted ring without traces of solder. Or it is formed from a wire where the ends of which are soldered. The third possible manufacturing method is the lost wax casting processes, specifically using gold granules: First, a sketch of a jewelry idea is made, then this object is shaped and carved out of wax. Afterwards the actual casting mold – a negative model of metal – is produced from this wax model. Then the real pouring of the gold takes place by melting the granules, and then pouring the mass into the cuvette. After cooling, the piece of jewelry is cleaned of the investment material.
The ring is now shaped by precise grinding and then polished. Valuable rings are freed of all burrs, edges and unevenness by hand in the final production steps. This is referred to as overcasting – a task that requires experience. A high-quality ring should feel smooth and supple.
In order to set a piece of jewelry with diamonds, gemstones or pearls, frames can be worked into the gold. Nowadays, these settings are usually drilled out by using CNC machines yet the actual insertion of the stones is reserved for the hand of the master.
Decoration options for gold jewelry
But gold itself, without other accessories such as pearls or diamonds, can be worked in beautiful ways. Quite a few decoration techniques have emerged over time, whereas I would like to present those which results fascinate me the most.
A popular technique in goldsmithing today is matting, by which a piece of jewelry is lend an attractive and unique finish. This is done with the help of a matt-brush that is equipped with fine wire bristles. There are different matting methods: longitudinally-matt with fine strokes (fine-matt); crosswise-matt, a finish which is considered very luxurious and for which a polishing brush can be also used; diagonally- or optique-matt, usually at a 45 degree angle; so-called ice-matt, by brushing in a crossed manner; and sand-matt where the surface is treated by sandblasting with quartz sand. Thus gold jewelry does not always have to shine brightly to be high-quality.
Engraving: Using a so-called graver, in classic hand engraving ornaments, characters, symbols or other decorations are engraved into the gold. Where material has been removed, the depressions can also be filled with other materials to create strong color contrasts. In modern jewelry, such decorations are often created by using laser engraving.
The term ‘filigree‘ refers to grained gold wire, known as such in the goldsmith’s art. During filigree work, the fine gold wires are folded, bent and regularly braided into sometimes elaborate shapes and patterns.
In the ancient decoration technique of granulation, small gold balls are soldered at their points of contact and added to ornaments or even three-dimensional arranged structures. On these art objects light refracts in a very interesting way and creates pleasant contrasts between bright and dark.
A hallmark is an embossing that is made with a so-called hallmark iron. As already explained, this is used to imprint the gold content of a piece of jewelry into its material. But hallmarks can also consist of extensive patterns, which are carved out in relief with the iron.
Etching: Using hydrochloric acid fumes – in the case of gold of the so-called ‘royal acid’, figures, symbols and other forms can be etched into the surface of gold jewelry. A protective top coat is applied to all surfaces that are not to be treated. The decorations can be created as high etching where the surrounding material is vaporized so that they may rest on it, or as deep etching where the decorations themselves are etched into the material.
During a process named ‘exchange‘, soft precious metals such as gold are pressed into previously carved depressions in harder metals. Next to the technique of large-scale replacement such as on belt fittings made of iron or steel, even the finer line replacement with hammered-in gold wires is a possible one.
Driving, hammering, chasing – these three techniques also belong to the most interesting hand skills in goldsmithing using the corresponding ‘driving and chasing hammer’. Driving means bringing a flat piece of metal into a concave or convex shape using the ball side of the hammer. Chasing, on the other hand, is the driving in of ornaments with different hallmarks, using the flat side of the chasing hammer. When hammering, the gold is worked on a harder surface and is not softened; the hits are more visible and thin gold waves just after a short, practiced treatment.
The different colors and types of gold alloys
Depending on the metal(s) which are added to pure gold, the alloy’s composition determines the coloring of the gold, which can range from very subtle undertones to unconventional, bold hues, and which can also influence the appearance of the jewelry.
Yellow gold is made from gold, silver and copper. Copper turns the metal slightly red, while silver lightens the color. Depending on the mixture ratio, the shades may vary from light yellow to a rich yellow-orange. In comparison, pure gold shines more yellow.
Red gold is typically a mixture of fine gold, copper and optionally some silver. The tone is determined by ta higher percentage of copper which gives the gold a modern look. The more silver and maybe palladium the alloy contains, we talk about rosé gold and lends the jewel a soft touch.
White gold is a collective term for all alloys where gold is mixed with palladium, silver or platinum. The color variations range from a kind of silver finish to a radiant white gold remembering the starlight.
Gold jewelry is usually ideal for allergy sufferers, as allergic reactions to gold are almost unknown. Nickel is occasionally used to make white gold; jewelry made from nickel white gold jewelry should therefore be avoided by people with a nickel allergy.
Some ‘golden’ extension: Quite common in the (high end costume) jewelry world is gold plating. Such gold-plated jewelry is essentially where another metal goes through a process named ‘electroplating’ to cover it with a layer of gold to create its finished look. Hereby a certain thickness of plating is required so that the coating might not be damaged. This kind of technique is also often used in the high end fashion watches industry to cover stainless steel.
Enchanted by the magic?
