To properly clean your metal finds, you need to know exactly which metal you are dealing with. This can be a difficult task as metals are often mixed into alloys for better performance or aesthetics. With this article I will try to give you a basic guide on identifying metals without going deep into the chemistry behind it.
Gold: Gold is definitely one of the easiest metals to identify. This metal requires basically no cleaning as it doesnt corrode in the ground like most metals. Gold usually has a yellow colour but can be found in white, red, orange and even purple as well. These types of gold are only used in expensive jewellery. Gold can be tested at a jeweller or at home using a special testing fluid.
Silver: Silver has a shiny grey/white colour. It does corrode in the ground and often turns black, brown or blue. Silver is a soft metal and can often be bent by hand. However, I don't recommend to try this as you might damage your find. It is used for different purposes; jewellery, decorations, cutlery, coins, etc.
Copper: Copper is a reddish metal. It is used in many different alloys, including gold alloys. The most frequently found copper alloys are bronze and brass. Pure copper will have a red core under the corrosion. Brass will have a yellow core. Bronze is the most tricky one as it's basically the chameleon of the metals. It can come out of the ground in many different colours. Most often, it will be green, brown or black.
Iron: Iron is very easy to recognize. It is usually covered in a very thick layer of rust which has a brown or black colour. In case you are uncertain, try to stick it to a magnet. If it sticks, it is either iron or steel. Iron is everywhere and it's often not what you're hoping to find. Most detectors will filter out iron or give a very bad signal.
Lead: Lead is heavy and soft. You can very easily bend lead objects. Lead becomes very crumbly in the ground and is often white or grey. It can also have blue spots. Lead is used in ammunition, weights, etc. Especially in fields you will find a lot of lead in musketballs and other types of old ammunition.
Nickel: Nickel looks very much like silver. It has the same colour and even the corrosion can look the same. The easiest way to differentiate them is by doing a magnet test. Nickel will stick to a magnet whereas silver will not. Furthermore, silver is a soft metal and nickel is a strong metal.
Aluminium: Aluminium can look like silver as well. Some countries have made coins out of aluminium. These are easy to recognize as they are very light. Aluminium is more often used in bottle caps, cans, foil, etc. When it comes out of the ground it can have a black or yellow colour.
Metal | Original colour | Colour from ground | Used since | Magnetic |
Gold | Yellow | Yellow | 3000 BC | No |
Silver | Silver | Black/Blue/Brown | 3000 BC | No |
Copper | Red | Green/Brown/Black | 10.000 BC | No |
Bronze | Red/Yellow | Green/Brown/Black | 3300 BC | No |
Brass | Yellow | Green/Brown/Black | 500 BC | No |
Iron | Grey | Dark Brown | 1200 BC | Yes |
Lead | Grey | White/Blue | 3000 BC | No |
Nickel | Silver | Grey/Black | 1800 AD | Yes |
Aluminium | Silver/White | Yellow/Grey/White
| 1800 AD | No |