Silver has been use for thousands years ago for decoration, being equipment, for trade, and as the basis in monetary system. Silver does not the highest value of all metal, but it is the second only to gold. Even though the silver jewelry is much cheap than gold jewelry, it still valuable and popular from consumer and jeweler who are just starting out and cannot afford to make pieces in gold.
Normally, jewelry silver are made from
sterling silver, as alloy 92.5% silver with 7.5% of copper. Thus the silver frequently stamped 925. But in U.S. the silver can contain at least alloy 90.0% silver with other metallic, this silver are stamped in 900. The reason that the manufacturer do not use pure silver is the sterling silver is harder and has lower melting point than pure silver. Sterling silver jewelry are often plated with a thin rhodium or gold for bright and shiny look.
The most popular method for making the shape of silver is lost wax casting. Lost wax casting is made by put the model of silver jewelry between the several sheet of rubber in the silver box container. After the box container is heated in around 300 degree Fahrenheit, the rubbers are melted and cover all of the model. When the rubber has hardened, the solid block is cut in half revealing a perfect mold of the original desired design. This rubber block can be reused to make thousands of wax copies. Then injected the warm liquid wax with a syringe through a hole cut into the rubber block. When the warm wax hardens, the wax design is created. After that put the wax ring inside the small flask and fill the investment
(powdered substance mixed with water that is similar in consistency to liquid plaster) around the wax model slowly to guard against bubbles of air left in the flask. The investment takes about 10 minutes for harden. Next, baking the flask which contained wax and investment in high temperature for several hours for a result of the wax to be lost by melting and evaporation. After the flask is cooled, the caster will place the flask in a casting machine for use a vacuum to draw molten silver into the mold. After the processing of casting machine finished and take a time for silver cooling down and harden, you can take the silver out from the flask and carving the investment out. The last processing is wash the silver, polish, and thin plate with fine silver or rhodium for more bright and shiny.
Reference:
http://www.emporia.edu/earthsci/amber/go340/silver.htm
Picture Credit:
http://www.jewelryschool.net/waxdesign.htm
