There are several ways to tell brass from copper:
Color: Copper is a bright red color, sometimes with a hint of orange or yellow. Brass is yellow to golden, depending on the zinc content.
Magnetism: Copper is nonmagnetic and is not attracted to magnets. The magnetism of brass depends on its alloy composition, but most brass alloys are also nonmagnetic.
Weight: Copper is slightly denser than brass, so copper is slightly heavier for the same volume.
Hardness: Brass is generally harder than copper because the addition of zinc increases the hardness of the alloy. The difference in hardness can be felt through a scratch test or an indentation test.
Conductivity: Copper is more conductive than brass because the zinc content in brass reduces its conductive properties. It can be distinguished by measuring resistivity.
Chemical testing: The purity and alloy composition of copper can be detected through chemical reagents, such as a spot test using nitric acid, where brass will gradually dissolve, while copper will not.
Spectral analysis: This is a more accurate detection method that can determine its chemical composition by analyzing the spectrum of the material.
X-ray fluorescence analysis (XRF): This is a non-destructive analytical technique that can quickly and accurately determine the chemical composition of a material.
Mechanical property testing: Brass and copper have different mechanical properties (such as tensile strength and yield strength), which can be distinguished by tensile testing.
Manufacturing process: Knowing the manufacturing process and source information of the material can also help with identification, because different production processes may affect the characteristics of the material.
Price: Generally, the price of copper is higher than that of brass, but price is not a reliable method of identification because market prices are affected by many factors.
In actual operation, it may be necessary to combine multiple methods to ensure the accuracy of identification. If precise results are required, it is recommended to use professional chemical or physical testing methods.