Keychain Neodymium Magnet for Testing Brass, Gold, Silver, Coins, Ferrous Metals Keychain Neodymium Magnet for Testing Brass, Gold, Silver, Jewelry. Coins and Ferrous Metals This keychain magnet offers strong magnet power in a handy keychain. It is perfect for jewelers, recyclers, coin dealers, or anyone that needs to make fast assessments of jewelry, antiques, and industrial metals for iron, nickel, or cobalt content. Determine if jewelry is silver or gold plated by testing if ferrous metals are used as the base metal (excluding some nickel alloys). If a magnet responds to jewelry, it is not fine silver or anything near pure gold. The same is also true of brass and bronze antiques, many are just brass plating over steel or iron. The magnet can also be used to determine polished aluminum from stainless steel in most cases, and is very handy for testing industrial metals for recycling. Featuring a durable neodymium magnet housed in a metal shell, it holds over 1.5 pounds. It comes with a stainless steel split ring. Use it for: Identifying most steel grades and metal alloys that contain iron, nickel, or cobalt. Identify/sort chrome plated items from polished aluminum, silver, and non-magnetic grades of stainless steel (chrome plating requires a nickel layer, which is magnetic). Identify and sort solid brass and bronze from steel plated items (handy in the antique market and hardware store). Identify fake/plated jewelry, which often has steel or nickel alloys as the base material (some alloys, like nickel-silver and German silver are non-magnetic, despite having ferrous metals present). Generally, the magnet test is only the first test performed, before density and acid testing. Hanging keys, notes, pictures, blueprints, etc. Also handy for science experiments and demonstrations involving ferromagnetism. Product Specifications TypeNeodymium Magnet Keychain MaterialN35 Neodymium Dimensions0.47 inches wide at its widest point x 1.57 inches long (12 x 40 mm) Net weight1.2 oz (34 g) Package Includes 1x Neodymium Magnet Keychain (other accessories are not included)