How can tell what metal gold electroplate is over?

To determine what metal gold electroplate is over, you can conduct a few tests. One common method is to use a magnet; if the item is attracted to the magnet, it may be plated over a ferrous metal like steel. Additionally, you can look for any wear or scratches where the underlying metal may be exposed; this can reveal the base metal color. For a more precise identification, a professional appraiser can use tools like an acid test or X-ray fluorescence (XRF) analysis.