Black Hills gold jewelry is a type of jewelry manufactured in the Black Hills of South Dakota. It was first created in the 1870s during the Black Hills Gold Rush by a French goldsmith named Henri LeBeau, who is said to have dreamed about the design after passing out from thirst and starvation. Black Hills gold jewelry depicts leaves, grape clusters and vines, and is made with alloys of gold with standard yellow gold as well as green and pink gold. [1] [2] In 1980, the 8th Circuit affirmed an injunction ruling that if a manufacturer was to call its jewelry Black Hills Gold, then it must be made in the Black Hills. [3] The state of South Dakota designated Black Hills gold as the official state jewelry in 1988. [4] [5]
The designs use grapes, grape leaves and grape stems and are easily recognizable for their distinctive colors. Silver is alloyed with the yellow gold to produce the green hue, and copper is alloyed with the yellow gold to make the red or pink gold. The jewelry was originally made with South Dakota-mined gold but in more recent years, since the closure of the Homestake Mine, the gold is sourced elsewhere. [6]
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Pure 24 Karat gold bars, and stocks of pure silver and copper are the basic materials. These metals are not required to be mined in the Black Hills. The finished jewelry known as Black Hills Gold must be produced in the Black Hills of South Dakota.
The different colors of gold used for leaves and other details are made when the pure 24 Karat yellow gold is alloyed with copper to achieve the traditional 14 karat pink (or red) gold, and the gold is combined with silver to create the 14 karat green gold. The resulting gold bars are then readied for rolling.
The alloyed gold bars are rolled by presses to different thicknesses for different types of jewelry. Each part is individually stamped out of the rolled gold sheets using patterns and dies. The solid gold leaves and other patterns are then added to a cast jewelry base.
The cast pieces are then polished by one of two methods, either traditional hand polishing using a wheel, or a process called "tumbling." For tumbling: many castings at one time are placed in a tub or cylinder with different sizes and shapes of metal, rubber or other materials in a liquid solution, then agitated or rotated until they have been polished smooth. These smooth, cast pieces are then ready for the stamped components, like leaves and grapes, to be mounted on them.
Some manufacturers, such as Landstroms, use the traditional method to attach the pieces, where the stamped components are individually hand-soldered to the cast gold frame using torches and karat-gold solder. Other factories place the solder and components together on the cast item, leaving several such assemblies in a soldering oven where they are soldered by the heat of the oven.
The almost-finished jewelry is cleaned in a mild acid bath, then inspected for quality. A finishing technique known as "wriggling" textures the leaves, creating a textured or frosty effect. Each leaf vein is then hand-engraved.
Each piece is polished in several different steps to bring out its brilliant luster. If the item has gemstones in its design, it is sent to the stone setting department for mounting, before final inspection.
Gold is a chemical element with the symbol Au and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental, as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver, naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium.
Solder is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable for use as solder should have a lower melting point than the pieces to be joined. The solder should also be resistant to oxidative and corrosive effects that would degrade the joint over time. Solder used in making electrical connections also needs to have favorable electrical characteristics.
Sterling silver is an alloy of silver containing 92.5% by weight of silver and 7.5% by weight of other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925.
Metalworking is the process of shaping and reshaping metals to create useful objects, parts, assemblies, and large scale structures. As a term it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale: from huge ships, buildings, and bridges down to precise engine parts and delicate jewelry.
A silversmith is a metalworker who crafts objects from silver. The terms silversmith and goldsmith are not exactly synonyms as the techniques, training, history, and guilds are or were largely the same but the end product may vary greatly as may the scale of objects created.
A goldsmith is a metalworker who specializes in working with gold and other precious metals. Nowadays they mainly specialize in jewelry-making but historically, goldsmiths have also made silverware, platters, goblets, decorative and serviceable utensils, and ceremonial or religious items.
Brazing is a metal-joining process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, with the filler metal having a lower melting point than the adjoining metal.
Mokume-gane (木目金) is a Japanese metalworking procedure which produces a mixed-metal laminate with distinctive layered patterns; the term is also used to refer to the resulting laminate itself. The term mokume-gane translates closely to "wood grain metal" or "wood eye metal" and describes the way metal takes on the appearance of natural wood grain. Mokume-gane fuses several layers of differently coloured precious metals together to form a sandwich of alloys called a "billet." The billet is then manipulated in such a way that a pattern resembling wood grain emerges over its surface. Numerous ways of working mokume-gane create diverse patterns. Once the metal has been rolled into a sheet or bar, several techniques are used to produce a range of effects.
In modern Western body piercing, a wide variety of materials are used. Some cannot be autoclaved, and others may induce allergic reactions, or harbour bacteria. Certain countries, such as those belonging to the EU, have legal regulations specifying which materials can be used in new piercings.
The fineness of a precious metal object represents the weight of fine metal therein, in proportion to the total weight which includes alloying base metals and any impurities. Alloy metals are added to increase hardness and durability of coins and jewelry, alter colors, decrease the cost per weight, or avoid the cost of high-purity refinement. For example, copper is added to the precious metal silver to make a more durable alloy for use in coins, housewares and jewelry. Coin silver, which was used for making silver coins in the past, contains 90% silver and 10% copper, by mass. Sterling silver contains 92.5% silver and 7.5% of other metals, usually copper, by mass.
Tumbaga is the name for a non-specific alloy of gold and copper given by Spanish Conquistadors to metals composed of these elements found in widespread use in pre-Columbian Mesoamerica in North America and South America.
Gold plating is a method of depositing a thin layer of gold onto the surface of another metal, most often copper or silver, by chemical or electrochemical plating. This article covers plating methods used in the modern electronics industry; for more traditional methods, often used for much larger objects, see gilding.
This article refers to the jewelry of the Etruscan civilization and its differences in various eras.
A bench jeweler is an artisan who uses a combination of skills to make and repair jewelry. Some of the more common skills that a bench jeweler might employ include antique restoration, silversmith, Goldsmith, stone setting, engraving, fabrication, wax carving, lost-wax casting, electroplating, forging, and polishing.
Wire wrapping is one of the oldest techniques for making handmade jewelry. This technique is done with jewelry wire and findings similar to wire to make components. Wire components are then connected to one another using mechanical techniques with no soldering or heating of the wire. Frequently, in this approach, a wire is bent into a loop or other decorative shape and then the wire is wrapped around itself to finish the wire component. This makes the loop or decorative shape permanent. The technique of wrapping wire around itself gives this craft its name of wire wrapping.
Metals used for architectural purposes include lead, for water pipes, roofing, and windows; tin, formed into tinplate; zinc, copper and aluminium, in a range of applications including roofing and decoration; and iron, which has structural and other uses in the form of cast iron or wrought iron, or made into steel. Metal alloys used in building include bronze ; brass ; monel metal and nickel silver, mainly consisting of nickel and copper; and stainless steel, with important components of nickel and chromium.
Pure gold is slightly reddish yellow in color, but colored gold in various other colors can be produced by alloying gold with other elements.
Soldering is a process in which two or more items are joined by melting and putting a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoining metal. Unlike welding, soldering does not involve melting the work pieces. In brazing, the work piece metal also does not melt, but the filler metal is one that melts at a higher temperature than in soldering. In the past, nearly all solders contained lead, but environmental and health concerns have increasingly dictated use of lead-free alloys for electronics and plumbing purposes.
Granulation is a jewellery manufacturing technique whereby a surface is covered in spherules or granules of precious metal. The technique is thought to have its origins in Sumer about 5,000 years ago. This technique then spread to southern Europe during the orientalizing period, also through the role of Phoenicians, who had founded colonies in Sardinia, Sicily and Spain, or Near Eastern craftsmen.