Brass is made from varying alloys of copper mixed with a second metal, often zinc. The word for 'brass', we have found, doesn't even exist in certain languages as brass is often considered a base metal or an industrial metal and is often better understood as a relative of bronze. Brass has been used as an industrial metal in the U.S. for over a century, and 'jeweler's' brass has been used as a base for costume jewelry in the U.S. dating back to the 1900's.
Contrary to what its name implies, gold filled jewelry is not actually "filled up"with gold. Gold fill is a hybrid material which consists of a layer of gold which is mechanically bonded, after being heat set, to one or both sides of a base metal, most often jewelers’ brass (Fig 1 & 2). The bonded metal is then rolled out into sheets to be made into jewelry. The amount of gold in the final product is at least 5% of the total metal weight (in comparison to gold plating, which is microns thick).
The process to create this material was patented in England in 1817 and became a popular material for women’s costume jewelry during the Victorian era and remained popular through the 1940’s roughly.
Early hallmarks for 19th century might include stampings such as ‘Gilt’ or ‘Rolled Gold’ while later in the 20th century, articles made from gold-fill would be expressed as a fraction which denotes the proportion of gold to base metal, along with the karat of gold used i.e. “1/20 12K G.F.”
Brass can and will tarnish, either slowly over time as the copper within brass is exposed to air and eventually oxidizes (darkens), or quickly in response to exposure to certain other elements. Tarnish and darkening of brass is not permanent. Should any of this tarnish wear off on your skin, it isn't permanent either. Tarnish can be removed from skin with soap and water. Tarnish is not known to stain clothing. Tarnish can be removed from the surface of brass by several methods. Gentle cleaning can be done with a silver polishing cloth and some elbow grease--rub gently et voila! This will be the most subtle method. More deep cleaning requires an acid of some kind to cut through the layer of tarnish. We recommend natural acids for this such as lemon juice or white vinegar. Simply dip a soft toothbrush into the cleanser of your choice, and brush over all tarnished areas. Rinse and then dry with a soft cloth. If you prefer a commercial product, we recommend Brasso which can be found in hardware or grocery stores.
HOW TO CARE FOR STERLING SILVER
Care recommendations for silver are the same as for silverware, and other sterling silver jewelry: use a polishing cloth for light surface cleaning, and use a liquid or paste to cut through oxidization (tarnish) for deep cleaning. Tomato paste or ketchup are effective natural cleansers and can be applied with a soft brush or cloth, followed by a round of rinsing and drying with a soft cloth. For a commercial product, we recommend Godard's silver polish.