Gold and brass are both bright yellow metals. Knowing how to tell them apart can be tricky for someone with little experience in the field of metals. Fortunately, there are several ways to differentiate one from the other. For those who know what to look for, there are often marks on the metal that identify its nature. The physical and chemical properties of the metal can also be tested to determine whether it is gold or brass.
Steps
Method 1 of 3: Observe the Physical Properties
Step 1. Examine the color
Although gold and brass have a similar color, the former is certainly more yellow and bright. Brass has a duller and less vibrant hue than pure gold. However, if gold has been mixed with other metals, this method is not fully reliable.
Step 2. Touch the object with a magnet
Unlike brass, gold does not react to magnetic fields. Bring the magnet close to the metal and see if it is attracted or not. If it is attracted, it means that it is brass, otherwise the metal in question is gold.
Step 3. Rub the metal against a ceramic surface
Gold is a very soft metal, so rubbing it against a ceramic surface will leave a golden streak behind. Brass, on the other hand, being harder, will leave a black stripe. Simply slide the metal against an unglazed ceramic surface.
Step 4. Test the density of the metal
The most accurate way to verify it is to measure the mass and volume of the object and then calculate it mathematically. Fortunately, there is also a simpler and faster approach. Lift the metal up a little with your hand, then let it fall to the surface below (or lift and lower it while holding it in your hand). Since gold is denser than brass, it will feel heavier than you expected. On the other hand, if it is brass, you will have the feeling that it is lighter than it should, because it has a low density.
Method 2 of 3: Locate the Metal Identification Marks
Step 1. Look for the brand that identifies the carats
The carat is the unit of measurement used to mark the purity of gold. In gold alloys, a high percentage of gold compared to other metals is indicated with a high carat number. Pure gold is 24 carat, while brass is not marked with carats. Generally this mark is placed in an inconspicuous area, for example on the bottom or inside an object or a jewel, even if there is no rule on this.
Step 2. Look for the brass identification code
Although the brass is not marked with the number of carats, it does sometimes carry a code or an abbreviation. On many objects the mark is stamped or engraved somewhere on the metal at the time of forging. Just like gold, there is no rule that dictates where the code goes, but it is generally located inside a border or on the bottom.
Step 3. Find out about the price
Knowing how much the item is being sold for, you won't have a hard time figuring out if it's gold or brass. Gold is quite expensive based on the degree of purity. Brass is relatively inexpensive compared to precious metals, such as gold and silver.
Method 3 of 3: Testing the Chemical Properties
Step 1. Look for signs of oxidation
One of the most popular properties of gold is that it does not oxidize. On the contrary, the oxygen present in the air causes the brass to oxidize. This reaction, called oxidation, causes the appearance of an unsightly dark patina on the metal. If the object in question has oxidized areas, it means that it is made of brass. However, the absence of oxidation is not sufficient to affirm that the metal is gold.
Step 2. Test the chemical properties of the metal on a small hidden area
If you want to carry out this type of verification, it is important to choose a point that is generally not visible. This way you can be sure that the object will not be damaged. You can choose the inside of an edge or flap or a point on the metal that is normally covered or hidden.
Step 3. Drop a drop of acid on the metal
Use concentrated acid. Unlike gold, brass reacts to acids. If the color or texture of the metal changes where you applied the acid, it means it's brass. If you don't notice any changes, you are the lucky owner of a gold item.
Warnings
- Acids are toxic and corrosive, so be very careful.
- Using acid on an expensive item could compromise its value.
