Brass is a highly durable metal that is commonly found in antiques and artifacts. Many collectors search for brass items as they can be rather valuable. Unfortunately, many metals resemble brass, which can make it difficult to identify a brass item. However, various methods can determine whether you have found a brass antique or an antique composed of another metal. These tests, including magnetism and chemical reaction tests, will also help you identify whether your item’s makeup is solid brass or simply has a brass coating.
Inspect the metal object for oxidation marks or encrustations that are the result of oxidation. The markings usually appear in a bluish or greenish tint on the metal along with some rust spots.
Remove the oxidation and rust with a varnish cleaner. Soak the object in a solution of 5 to 10 percent citric acid until the oxidation has come off. It might take anywhere from an hour to various days for the oxidation to dissolve. Stir the citric acid periodically.
Clean the metal object with a brass stripper and stripping product to better view the metal’s color. Buff the metal surface with a steel wool cloth.
Check the metal’s color now that it is polished. A metal object that is relatively yellow is identified as brass. Other metals such as copper generally have pink tints and tones. Brass is also stronger than copper, which is usually more malleable.
Place a magnet close to the brass. If the object attracts the magnet, the object is not solid brass. However, it might have a brass plating.
Apply a small amount of hydrochloric acid to an area of the brass. Test only a small area because the test is corrosive. Unlike some metals, brass turns pink when it is tested with hydrochloric acid.
- Varnish cleaner
- 5 to 10 percent citric acid solution
- Brass stripper/stripping agent
- Steel wool cloth
- Hydrochloric acid
Use proper equipment, including gloves and eye protection, when handling hazardous materials like hydrochloric acid.