Whether the metal to be used is gold or silver, the same methods or steps are followed when making the jewelry.
A. Melting and Sheet Casting
1. The first step in this process is annealing or heating the metal at a predetermined temperature. (This method is essential in melting a metal.) During the melting process, the gold or silver being worked is placed in a clay pot and melted using a blow torch. (The same container is also used when gold or silver is being alloyed to improve its hardness and to prevent having a deformed jewelry.)
The varying temperature for melting silver or gold is:
- Fine silver: 1761°F
- Sterling silver: 1640°F
- 18K white gold :1945°F
- 18K yellow gold :1700°F
- 14K white gold :i825°F
- 14K yellow gold : 1615°F
2. Once the gold or silver is melted, this is poured into a sheet mold (shaped like a U”) so that this can be molded into a small bar.
3. Because of heat exposure, this small bar which has been shaped after melting the metal, is commonly coated with a thin oxide film.
The bar is dipped into a sulfuric acid solution and water to remove the oxide film from its surface. The oxide film must be removed so that the metal can easily be welded during the soldering process. (The sulfuric acid solution dipping gives the treated metal a surface that assists in soldering.)
4. After removing the oxide film, the metal passes through a rolling press for beating into its desired thinness. The gold or silver being worked passes through the rolling press several times until the desired thinness is attained.
B. Sawing and Cutting
The second step involves forming the gold or silver into its desired shape. Several techniques can be applied. Some of the common methods are sawing and cutting. The metal is cut using a special saw, called a jeweler’s saw.
Wiring is another method wherein the gold or silver is heated and stretched into the shape of a wire. Two important tools are used in shaping the gold or silver wire – the wire plate and the roller press. This metal wire is utilized in making intricate jewelry designs like filigree and chained necklaces.
A metal is also shaped by method. In this process, the metal is placed inside a centrifugal machine where the mold is attached. This process is more often used in mass production of jewelry. (The operation of casting metals in liquid state varies widely according to the form in which the metal will finally be used).
C. Soldering and Assembly
In this step the different parts of the jewelry being made are arranged or joined together by soldering in order to complete the design.
D. Filing and Forming
Once the jewelry parts are fully assembled, they are subjected to filing and forming, during which the edges and corners of the completed jewelry are polished using different types of files.
Stonesetting involves the insertion or mounting of precious or semi-precious stones in the gold or silver jewelry. Sometimes, transparent stones, according to their color, are placed on a gold or silver base to increase the amount of light reflected.
F. Polishing and Plating
Polishing and plating are done to enhance the jewelry’ brilliance with the help of a polishing motor.
The metal is also given surface treatment to produce a protective layer which is corrosion-resistant and to improve the surface appearance of the jewelry metal. This process is called plating or electroplating. In this method the metal is dipped into a gold or silver plating solution. The bath provides a thin coating, which adds sparkle to gold or silver jewelry and also increases, its durability.
source: TRC Business Guide, www.trc.dost. gov.ph, photo from www.freedigitalphotos.net