Monel is an alloy metal, which means that it is a combination of various metals and minerals, according to Lenntech.com. Monel is comprised of nickel, copper, iron, manganese and smaller amounts of other types of compounds. It was discovered in 1901 and the name Monel is trademarked by the Special Metals Corporation. Since Monel has an appearance similar to other metals, it can sometimes be difficult to identify it by sight. Identifying it requires testing the properties of the object to determine if it is Monel.
Hold a magnet near the metal object and see if there is a slight magnetic pull which indicates that it may be Monel. The magnetic pull will not be as strong as with a metal like steel, but you should feel a minimal attraction. If there is no magnetic pull, the metal is not Monel.
Fill a medicine dropper with nitric acid and place one drop onto the metal surface in an inconspicuous location. Observe the metal for a few seconds to see if it turns a blue-green colour, which indicates that the metal is Monel. The colour is a chemical reaction between the nitric acid, the copper and nickel contained in the Monel.
Examine the entire surface of the metal object and look for signs of rust. If rust is present, the metal is not Monel. Monel does not rust and is most frequently used in marine construction.
Look for a green or brown build-up around sections of the metal that are attached to bolts or hinges. These discolourations indicate that the metal is Monel.
Nitric acid is available for purchase from companies that sell lab equipment.
Nitric acid produces toxic fumes and should only be used in a well ventilated area. In addition, proper safety gear including rubber gloves and a face mask should be worn.