A brief description of the main base metals used in jewelry:
Gold is an alloy, or mix, of different metals. It is highly prized for its rich yellow color and luster. Gold is measured in a ratio called karat (K) based on the amount of gold in the alloy metal. 24K gold is pure gold, and is most often used for gold plating of other base jewelry metals.
The other commons gold alloys are 10K, 14K, and 18K. Respectively, these alloys contain 41.7%, 58.3%, and 75% pure gold. The color of gold is dependent on the karat and the other metals that are mixed with the gold, most commonly silver and zinc. For example,
- Yellow gold is most commonly pure gold mixed with silver and zinc. 18K yellow gold will be a richer color than 10K due to the higher % of pure gold.
- White gold combines pure gold with silver or nickel.
- Rose gold combines pure gold with copper.
Silver has long been used as a primary metal in jewelry making. The most common silver used in fine jewelry is Sterling Silver, which is 92.5% silver and 7.5% copper. This is why Sterling Silver is also referred to as 925 silver or stamped with 925. The copper strengthens the alloy, making 925 silver a great material for jewelry. Sterling Silver is a hypoallergenic metal, and its luster can easily be maintained with a polishing cloth and by protecting the jewelry from moisture and chemicals.
Stainless Steel is very durable and maintains its shine and luster. It may be alloyed with titanium and/or nickel. Since nickel is in the alloy, it has the potential to aggravate skin that is very sensitive to nickel. Stainless Steel often a more affordable base metal for jewelry and is often used in fashion jewelry.
Copper-Based Alloys (Bronze and Brass)
These alloys have a desirable golden tone and are inexpensive. Due to their low cost, they are often used in fashion or costume jewelry. The copper in these alloys can tarnish and can affect sensitive skin. Protecting the piece from water and chemicals should prevent this. Brass is made from copper and zinc Bronze is made from copper and tin.