TL;DR
Gold itself is nearly indestructible by household standards -- the risk is always the stones and the settings. A ten-minute soak in warm water with a few drops of mild dish soap, followed by a very soft brush and a thorough rinse, cleans most gold jewelry. The exceptions are soft or porous stones, glued settings, and anything with chlorine exposure.
What actually dulls gold
Pure gold does not tarnish. What you see on a dull chain is a film of skin oil, sweat, lotion, hairspray, sunscreen, and soap scum, plus dust stuck to all of it.
Most jewelry is not pure gold, though. Fourteen and eighteen karat gold are alloys, mixed with copper, silver, zinc, or nickel for hardness and color. Those alloy metals can react, which is why lower-karat gold sometimes develops a faint dark film or leaves a mark on skin.
White gold adds another layer. Most white gold is plated with rhodium to get its bright white color, and that plating wears through over a few years, revealing a slightly yellow tone underneath. That is wear, not dirt, and replating is a jeweler's job.
Gold-filled and gold-plated pieces are a different category entirely -- see how to clean costume jewelry without ruining it before you scrub anything plated.
How do you clean gold jewelry at home?
Mix warm water with a few drops of mild dish soap, soak the piece for ten to fifteen minutes, brush gently with a very soft toothbrush, especially behind stones and inside chain links, then rinse in clean warm water and dry with a soft lint-free cloth.
The basic method, step by step
1. Plug the sink or use a bowl. Never work over an open drain. This advice is boring and it saves rings.
2. Warm water, a few drops of mild dish soap. Warm, not hot. Hot water can loosen adhesives and stress some stones.
3. Soak ten to fifteen minutes. Soaking does most of the work. Longer for heavy buildup, as long as the piece is safe to soak at all.
4. Brush gently with a very soft toothbrush. The important places are behind and under stones, where a surprising amount of grime collects and blocks light from entering the stone. That is why a cleaned ring looks brighter.
5. Get inside chain links. Grime hides there and it is the reason a chain looks gray rather than gold.
6. Rinse in a bowl of clean warm water. Not under a running tap over an open drain.
7. Dry and buff with a soft lint-free cloth. Let it air dry fully before storing, especially anything with a hollow section.
Which stones can be soaked and which cannot
This is where jewelry gets ruined, so it is worth being specific.
Safe to soak in mild soapy water: diamond, sapphire, ruby, most quartz including amethyst and citrine, garnet, spinel, topaz, aquamarine and other beryls in good condition.
Do not soak: pearl, opal, turquoise, coral, amber, jet, malachite, and lapis lazuli. These are soft, porous, or organic. Water alone can dull an opal or loosen a pearl from its glue, and detergent gets into pores and stays. Wipe these with a barely damp cloth instead -- see how to clean pearls without damaging them.
Handle carefully: emerald is commonly oil-treated or resin-treated to improve clarity, and hot water, detergent, and ultrasonic cleaning strip that treatment. Tanzanite and topaz can crack from thermal shock. Any stone held in with glue rather than prongs should not be soaked.
If you do not know what a stone is or how it is set, a jeweler can tell you in about a minute and most will clean it while you wait.
Chlorine, and why pools ruin gold
Chlorine attacks the alloy metals in gold, especially the nickel and zinc in lower-karat pieces. Over repeated exposure it causes stress cracking in the metal, which shows up as a prong snapping or a thin band breaking apparently for no reason.
That means take rings off before swimming pools, hot tubs, and any cleaning task involving bleach. Bleach damages gold jewelry directly, and there is no safe way to use it on a piece.
While we are here: never mix bleach with an acid, with ammonia, or with alcohol under any circumstances. Those combinations produce toxic gases, and there is no cleaning benefit that would justify the risk. Use one product at a time.
Salt water, chlorinated water, and hot tubs also loosen prongs over time. Rinse jewelry in fresh water if it has been in any of them.
What about ammonia and ultrasonic cleaners?
A very dilute ammonia solution is sometimes recommended for plain gold and diamonds, and jewelers do use it. At home it is easy to get wrong, easy to leave on too long, and unsafe near bleach. Mild dish soap does nearly as well with none of the hazard. If you want the ammonia-level result, take the piece to a jeweler.
Ultrasonic cleaners are a similar story. They are excellent on plain gold and hard stones and destructive on almost everything else: pearls, opals, emeralds, treated stones, glued settings, and any stone with an internal fracture. Home units also loosen prongs on lightweight settings. Use one only if you are certain about every stone in the piece.
Source: Federal Trade Commission Jewelry Guides and Gemological Institute of America consumer care guidance
Storage and everyday habits
Store pieces separately. Gold is soft enough that a diamond ring will scratch a gold chain sitting next to it in a dish. Individual pouches or a lined box with compartments solves it.
Put jewelry on last and take it off first. Lotion, perfume, hairspray, and sunscreen all leave film, and they are the main reason a piece needs cleaning at all.
Take rings off for cleaning, gardening, gym work, and dishes. Most bent prongs and lost stones happen during ordinary chores.
Have prongs checked by a jeweler every year or so if you wear a stone daily. Cleaning does not detect a loose setting, and finding one early is much cheaper than replacing a stone.
The same general routine of wash, dry, and store separately runs through cleaning the personal items you use every day and the tarnish-specific version in how to clean tarnished silver jewelry.
FAQ
Can you clean gold jewelry with dish soap?
Yes, and it is the safest home method. A few drops of mild dish soap in warm water, a ten to fifteen minute soak, and a very soft toothbrush will lift skin oil, lotion, and soap film from most gold pieces. Rinse in a bowl of clean water and dry with a lint-free cloth.
Can gold jewelry go in an ultrasonic cleaner?
Plain gold and hard stones such as diamond and sapphire usually tolerate it, but ultrasonic cleaning damages pearls, opals, emeralds, treated stones, and any glued setting, and it can loosen prongs. If you are not certain what every stone is and how it is set, have a jeweler do it instead.
Does chlorine damage gold?
Yes. Chlorine attacks the alloy metals mixed into gold and causes stress cracking over repeated exposure, which is why prongs and thin bands sometimes snap without an obvious impact. Remove gold jewelry before swimming pools and hot tubs, and never use bleach on it.
Why is my white gold turning yellow?
Most white gold is plated with rhodium to look bright white, and that plating wears through with daily use over a few years. The yellow tone underneath is the actual gold alloy. It is wear, not dirt, and a jeweler can replate the piece to restore the white finish.
Can you clean gold jewelry with toothpaste?
No. Toothpaste contains abrasives designed for tooth enamel, and gold is soft enough that those abrasives leave fine scratches and dull the polish. They also collect in crevices around settings. Mild dish soap and warm water clean better without damaging the surface.
How often should you clean gold jewelry?
Pieces worn daily benefit from a soapy soak every two to four weeks, since skin oil and lotion build up quickly and dull the shine. Occasional-wear pieces can go much longer. Wipe anything down with a soft cloth after wearing to slow the buildup between cleanings.
Jewelry takes minutes. The dresser, the bathroom, and the rest of the house take longer. If you would rather hand that off, get a quote or read more about house cleaning services.