The arrival of Brilliant: Cartier in the 20th Century at the Denver Art Museum this month reminds me of something important: If you want your fine jewelry to sparkle for years—if not decades—your gems need regular TLC. Whether it’s a diamond engagement ring or a cherished heirloom, precious metals and gemstones require delicate cleaning to maintain their shine. For expert advice on proper cleansing techniques, I turned to Gusterman’s Mary Eckels, who has owned the Larimer Square boutique since 1978. A master craftswoman herself (she apprenticed under original owner Astrid Gusterman), Eckels works with silver, gold, platinum, and natural stones. Here, she shares her tips for keeping your jewelry in museum-worthy condition:

Wash It. Jewelry requires mild cleaning. Try a mix of two tablespoons household ammonia, 1/4 cup water, and a dash of Dawn liquid soap. Place your bauble in the solution to soak for a couple minutes and then use a very soft toothbrush to gently scrub out oils, lotions, and grime. Note: Eckels suggests always having this solution on hand, pre-mixed in an empty jar. It can keep forever, but, she says, if you’re not running out with a small jar, you’re not cleaning your jewelry enough. Aim to wash your pieces one to two times per month. Works for: gold, silver, platinum, gemstones and pearls; avoid amber and malachite as they react with ammonia.

Polish It (Bright Jewelry). Wright’s Silver Polish (about $5) and Hagerty Silver Polish (about $7) are both available at drugstores and work well. Using a small rubber sponge, rub the polish over your jewelry in circular motions to brighten the metal. Always rinse the polish off with warm, soapy water so it doesn’t dry on its own and look chalky. A soft toothbrush will help get residue out of patterned areas. Note: Platinum will take a shine if rubbed with a polishing cloth (available at most jewelers). A separate cloth to be used only on platinum is recommended, as the metal will react to exposure from other metals’ particles. Works for: gold and silver; you can polish the metal around stones, but not the stones themselves (simply wash off if a little ends up on them); avoid getting polish on pearls, opals, and tanzanite.

Polish It (Matte Jewelry). A one-minute dip in Tarn-X silver polish (about $13) is all you need to strip the oxide (or tarnish) off any pieces. Wash off with cold water. Works for: matte sterling silver, silver plate, and textured silver; diamonds are safe in Tarn-X but not other stones.

Dry It. Once your jewelry is clean and polished, be sure to completely dry it using a soft terrycloth towel or even a paper towel. Note: Blow air into the stones and patterned areas to get all the water out.

Store It. Keep clean jewelry in small, sealed plastic bags that you can pick up from a hobby or hardware store (or the Container Store) and place them in a box that closes tightly. Storing jewelry pieces in separate bags with a tight seal keeps air out and silver and gold from discoloring.

Go Pro. If you have an important event coming up or just can’t get your jewelry as shiny as it used to be (platinum can be particularly difficult), bring it to a professional like Eckels for cleaning. Jewelers usually charge for this service and it can take some time, so plan accordingly. Eckels charges by the piece, based on the amount of work required; prices start at $5 per piece (although items made in her shop are cleaned free of charge and usually within 20 minutes). Note: It’s also worth a visit to a jeweler if you’re unsure of what kind of metal or stones your jewelry is made of or if you have any cleaning concerns.

(Check out five art-deco pieces inspired by Cartier)

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