What is the most reliable method to know whether an item of jewellery is made of real gold? Look to see if there is a gold hallmark on your jewellery. Sometimes this is very small and not immediately visible with the naked eye. In this case it can be read using a professional loupe. If you want to have 100% certainty about whether your gold jewellery is real, you can take it to a jeweller. They can weigh the gold and test it to make sure it is real.