What Not to Put in an Ultrasonic Jewelry Cleaner?

Do not put pearls, opals, emeralds, turquoise, coral, amber, tanzanite, or any porous or treated gemstone into an ultrasonic cleaner. These stones are highly vulnerable to the high-frequency vibrations ultrasonics produce. The same applies to any piece where stones are held in place with adhesive rather than mechanical settings – the vibrations will loosen or dislodge the stones. Solid gold and platinum pieces set with hardened natural diamonds are generally the safest candidates for ultrasonic cleaning.

The reason certain stones cannot handle ultrasonics is straightforward: the machine creates microscopic cavitation bubbles that collapse with significant force to remove dirt and debris. That same energy can shatter a stone with natural inclusions or fractures, delaminate the nacre on pearls, strip the coating from treated stones, or open up hairline cracks that were previously stable. Emeralds, for example, are almost always fracture-filled with oils or resins to improve their appearance – ultrasonics remove that filling rapidly and can leave the stone looking worse than before. Opals are porous and can absorb water from the cleaning solution, causing them to crack or craze. Tanzanite is brittle enough that the vibrations alone can fracture it.

Pieces that should never go in an ultrasonic cleaner include: pearl strands and earrings, opal rings and pendants, emerald jewelry, turquoise, coral, and amber pieces, any antique or heirloom piece with unknown stone treatments, items with glued-in stones or bezels sealed with adhesive, and jewelry with visible chips or cracks in the metal or stones. If you are uncertain whether a piece is safe, the answer is to err on the side of caution. A professional jewelry spa service – like QJR's in-house cleaning – uses the right method for each material rather than a one-size-fits-all ultrasonic cycle, which is why pieces come back clean without damage.