The Costume Jewelry Manufacturing Process
Brass
Brass is best described as a buttery yellow alloy of zinc and copper which has been manufactured for thousands of years all over the world. For jewelry, at least 67% copper and 33% zinc is used. Copper melts at 1083 Celsius and zinc boils at 907 Celsius and silver melts at 960 Celsius. Formulas with varying proportions of copper and zinc are alloyed together colors to achieve different variations of brass.
The color of the alloy will also vary, depending on the amount of zinc: brass gets lighter in color with additional zinc, and can reach a pale yellow stage. With this particular mixture, it helps the brass become stronger and more durable than copper alone, although not as strong as metals like steel. Thus, the perfect mixture for fashion jewelry. Although brass was often made by accident, early intentional brass was actually made with calamine, a mineral which contains zinc. By 200 BC, China was differentiating between brass and bronze, and in 300 AD, Germany and the Netherlands became well known in Europe for their brass.
In 1746, the properties of zinc came to be more generally understood, and England patented the technique for producing brass in 1781. Now brass is used to make several commodities offered in our markets, including Costume Jewelry!
Stainless Steel
Stainless steel used in fashion jewelry can be defined as a steel alloy with a minimum of 10% chromium content by mass. Stainless steel does not stain, corrode or rust as easily as ordinary steel (it stains less”). It is also called corrosion resistant steel when the alloy type and grade are not detailed, particularly in the aviation industry. There are different grades and surface finishes of stainless steel to suit the environment to which the material will be subjected in its lifetime.
Common uses of stainless steel are in watches, cutlery, and jewelry. Stainless steel differs from carbon steel by amount of chromium present. Carbon steel rusts when exposed to air and moisture. This iron oxide film is active and accelerates corrosion by forming more iron oxide. Stainless steels have sufficient amount of chromium present so that a passive film of chromium oxide forms which prevents further corrosion.
Thus it is extensively used in heavy gauge welded components such as jewelry. 316L stainless steel offers higher creep, stress to rupture and tensile strength at elevated temperatures. Therefore, ensures that all our stainless steel jewelry will never warp even if you run over it with a car!
.925 Sterling Silver
.925 sterling silver is an alloy of silver containing 92.5% pure silver and 7.5% other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925 when used for jewelry. Fine silver (99.9% pure) is generally too soft and malleable for jewelry; therefore, the silver is usually alloyed with copper to give it strength, while at the same time preserving the ductility and beauty of the precious metal.
Other metals can replace the copper, usually with the intent to improve various properties of the basic sterling alloy such as reducing casting porosity, eliminating fire-scale, and increasing resistance to tarnish. These replacement metals include germanium, zinc and platinum, as well as a variety of other additives, including silicon and boron.
A number of alloys have appeared in recent years, formulated to lessen fire-scale or to inhibit tarnish, and this has sparked heavy competition among the various manufacturers, who are rushing to make claims of having the best formulation.