How could you test your gold jewelry to determine whether it is a pure compound or a mixture?

Pure gold (100% Au) is soft and all gold jewelry I know of is a mixture of Au alloyed with another metal. Have you seen the old old movies showing a seedy looking settler being paid with gold. They bite the piece of metal. If it is soft it is pure gold.

To test your gold jewelry and determine if it is a pure compound or a mixture, you can use the following steps:

1. Obtain a small sample: Take a small piece or a tiny amount of your gold jewelry. It's important to focus on an area that is not visibly noticeable to preserve the appearance of the jewelry.

2. Visual inspection: Perform a visual examination of the sample. Observe the color, shine, and overall appearance of the gold jewelry. Pure gold tends to have a distinct golden-yellow color and a lustrous shine. If there are visible impurities, it may indicate that the jewelry is a mixture.

3. Magnet test: Hold a magnet near the sample. Gold is not magnetic, so if the jewelry is attracted to the magnet, it suggests it is a mixture and not pure gold. Keep in mind that some jewelry may have magnetic clasps or other non-gold components, so this test alone is not conclusive.

4. Density test: Use a density test kit or water displacement method to measure the density of your gold jewelry sample. Pure gold has a density of around 19.32 grams per cubic centimeter (g/cm³). Impurities or other metals in the mixture will alter the density, so if the measured density deviates significantly from 19.32 g/cm³, it suggests the jewelry is not pure gold.

5. Acid test: Perform an acid test using a testing kit designed for gold. This involves applying a small amount of acid onto the jewelry sample and observing the reaction. Pure gold will not react with most acids, while impurities or other metals will cause a color change or dissolution. Follow the instructions provided with the acid testing kit carefully.

It's important to note that these methods provide an indication but are not always definitive. For accurate and precise testing, it is advisable to consult a professional jeweler or a certified assayer who can use more advanced techniques such as X-ray fluorescence (XRF) or fire assay to accurately determine the composition of your gold jewelry.