Just as the sun’s harmful rays can damage our skin, light and heat can affect a colored gemstone’s durability and color. Over time, and in excess, they can also fade or damage some gemstones, such as amethyst, kunzite, topaz and shell cameos. Pearls and other delicate materials, such as ivory, will bleach under extreme exposure to light. Other gems, especially amber, can darken over time when exposed to too much light.
Excessive heat and sudden temperature changes may also fracture some gems. Heat can easily remove the natural moisture these gems need to keep their beauty. Pearls, for instance, can dry out, crack and discolor. Opals can turn white or brown, develop tiny cracks, and might lose their play-of-color.

Exposure to chemicals can damage or discolor precious metals – gold, silver and platinum – and may harm some colored gems. Even everyday substances like hairspray, lotion, perfume or other cosmetics can contain chemicals that will permanently damage the surface of your pearls and other delicate or porous gems (like turquoise). Fine jewelry should be removed before diving into a chlorinated swimming pool or before using household cleaners. Many of these cleaners contain ammonia, which can be too harsh for delicate gems or vintage jewelry. Chlorine bleach, another common household solvent, can pit or damage gold alloys.

While you can purchase a professional ultrasonic cleaner for €150 or less, you should be aware that not all gems and jewelry can be safely cleaned in it.

Ultrasonic cleaners should not be used to clean:
Gemstones with surface-reaching breaks that have been filled with a substance such as oil, resin or a glass-like material
Organic gem materials such as pearls, coral, ivory, or amber
Gems that have been coated with a non-permanent substance like plastic or wax
Some heat-treated gemstones
Gems that are susceptible to heat and temperature changes whether they are treated or not. Some of these gems include tanzanite, feldspar (sunstone and moonstone), fluorite, iolite, kunzite, lapis lazuli, malachite, opal, topaz, turquoise, zircon and others
What’s more, the vibration generated by the machine can sometimes shake gems loose or chip gems that are set with their girdles touching.

This type of cleaning is best left to jewelry professionals who know about different gem materials and understand when and how to use the ultrasonic cleaner safely.

Many colored gemstones are routinely treated to improve the appearance of color and clarity. These treatments can be negatively affected by heat, solvents, steam and ultrasonic cleaners. Knowing whether your gem has been treated is the first step to knowing how to care for it. This is where a GIA report comes in – it contains important information about your gem and any detectable treatments it may have undergone.

Most colored gems can be cleaned with warm water, mild dish soap (no detergents) and a soft brush. A pulsed-water dental cleaning appliance and a soft, lint-free cloth can also be used. Be sure to rinse your jewelry in a glass of water to remove cleaning solutions since you risk losing loose stones – or even an entire piece of jewelry – if you rinse directly in the sink.

Soft gems, such as pearls, on the other hand, can easily scratch. Use a new, clean makeup brush and warm, soapy water to softly clean them. Lay a strand of pearls on a towel to dry. The wet silk thread can stretch − and attract dirt − so don’t touch your strand until it is completely dry. Pearls worn often should be restrung once a year.

Proper jewelry storage is often overlooked. Jewelry should never be tossed into a drawer or on top of a dresser − that’s asking for scratches and damaged gems.

Most jewelry pieces come in a box or pouch from the store, which is a perfect place to keep them. Sterling silver, for example, should be kept in an anti-tarnish bag or cloth. Jewelry boxes that feature individually padded slots for rings and posts for hanging necklaces and bracelets are also ideal.

Diamonds are natural magnets for grease, so they’re not easy to keep clean. When a diamond is handled, the oils from your fingers adhere to the diamond’s surface and affect its brilliance and fire.

Chlorine bleach or abrasives (such as household cleansers or toothpaste) should never be used when cleaning diamond jewelry. Chemicals like chlorine can damage some of the metals used to alloy gold for diamond settings and abrasives can scratch gold and other metals.