Gold is timeless, but it can lose its shine. Sulphur can make gold dirty, but it won't damage it. You can clean sulphur off gold in a number of ways. You might need to merely wipe it with a jewelry cloth. However, most gold that is stained with sulphur will require soaking. Remember that the underlying gold won't change color or tarnish. Gold can always be restored to its mint condition.
Mix water with a mild detergent in a bowl or in any waterproof container large enough to hold the gold and the mixture. Mix enough to immerse your gold. Let it gold soak for 10 minutes. Use a soft brush to scrub off the sulphur. This could be a baby's toothbrush, an eyebrow brush or a brush made for jewelry cleaning, bought from a jewelry store. Rinse the gold. Dry it with a clean, soft cloth of the type used to clean glasses. Polish the gold until it shines.
Soak the gold in ammonia and water for 1 minute. Use one part ammonia and six parts water. Rinse the gold and scrub it with a soft brush. Polish it as you did in Step 1 with a glasses cloth or other soft cloth.
Wipe your gold with a jewelry-cleaning cloth that can be bought where gold jewelry is sold. This could be all that is needed to get rid of the sulphur, but you will probably have to soak the gold as in Steps 1 and 2.
Apply jewelry cleaner to a jewelry cloth and wipe the gold with it.