Manufacturing Process for Black Hills Gold Jewelry
Every major Black Hills Gold manufacturer's process is not identical to the one shown here. Some Black Hills Gold companies use additional steps, others have fewer steps with more automation, but the basic description would apply to all of the top Black Hills Gold brands producing Black Hills Gold jewelry today.
New Black Hills Gold jewelry designs begin with detailed drawings. After a design is selected, an actual size model of the item is created in wax. Sometimes silver and production models are created using the "lost wax" method of casting, which will be detailed later.
|Pure 24 Karat gold bars, and stocks of pure silver and copper are the basic materials. These precious metals are not required to be mined in the Black Hills, as some rumors contend. Pure gold and other precious metal stock can be acquired from anywhere in the world. The finished jewelry known as Black Hills Gold must be produced here in the Black Hills of South Dakota.
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|The pure 24 Karat yellow gold is alloyed with exact percentages of other metals to achieve a more durable karat quality of 10K, 12K or 14K, and used for ring shanks and the base of other items. 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 12 karat pink (or red) gold, and the gold is combined silver to create the 12 karat green. 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.||Component parts, or findings, are carefully stamped, one at a time, out of the rolled gold sheets using patterns and dies.|
|The solid gold leaves and other patterns are then ready to be added to a cast jewelry base, created using a method called "lost wax casting.||Lost wax casting begins with an original metal model, often silver, of a jewelry item. A vulcanized rubber mold is made from the metal model and is reusable for making a design over and over. A wax model is then made when hot molten wax is injected into the mold.|
|The wax model is removed from the mold and mounted to a wax stem called a sprue, which creates an airway for casting. Many designs mounted to this sprue create a "tree." The tree is place inside a stainless steel cylinder, and liquid investment compound (casting plaster) is poured around the wax patterns in the can. After the plaster hardens inside, the cylinder is placed in an oven and baked for several hours, melting the wax away. The cavity inside the hardened plaster provides an exact duplicate to be cast and is filled with molten gold. The cylinder is quenched in cold water, shattering the plaster and exposing the gold jewelry. The extra portions of the cast pieces where they were attached to the tree are ground away.||
The cast pieces are then polished by one of two methods, either traditional hand polishing using a wheel, or a process called "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 use the traditional method, 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.
|Some manufacturers again polish or tumble the assembled items, while others do not and polish using different methods. The jewelry is cleaned in a mild acid bath, then inspected using high quality standards. Then, each piece is electro-plated with 24 Karat yellow gold. A finishing technique known as "wriggling" removes the plating from the pink and green leaves, creating a textured or frosty effect.||Each leaf vein is then hand-engraved for a brilliant, light-catching finish. 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.|
|Finally, a careful inspection completes the process that began with pure 24 Karat gold and finished with a truly unique and beautiful, handcrafted jewelry item -- Black Hills Gold jewelry.||