Dull gold jewelry can result from using harsh jewelry cleaners. Many commercial jewelry cleaners contain chemicals that can strip away the plating revealing the base metal. If you must use a cleanser, opt for one that is safe for plated jewelry and follow the instructions on the bottle to avoid damaging your pieces.
If your jewelry pieces appear dull after cleaning them with soft toothpaste, silver polish, or other harsh jewelry cleaners, combine two to three drops of all-natural dishwashing liquid and a warm water solution and soak them for five minutes. Use a soft cloth to wipe away any remaining film from previous cleaners. Gently rub to avoid removing the gold and allow them to air-dry.
Sometimes, dull gold jewelry results from a plating that's too thin. When this happens, the jeweler can re-plate your jewelry with a thicker layer of gold. This process will transform your non-shiny gold into having a brilliant, long-lasting luster.
Other causes of non-shiny gold include a build-up of lotions, oils, and sweat on the surface of the metal. To correct this problem, clean your jewelry more frequently. Gently wipe them down with a jewelry cloth after each wear, and give them a deeper clean once a week using the dishwashing liquid and water solution.