Can ultrasonic cleaners damage small or brittle items?

With thousand of microscopic implosions every second you would have thought so. Ultrasonic cleaning is a very powerful way of removing contaminates from surfaces, however, the Cavitation is localised and at microscopic level. Care should be taken in choosing the correct cleaning medium – it’s far more likely that this could damage the parts than the ultrasonic action. Most dental and medical instruments are perfectly safe, as are clock and watches, although hairsprings should be cleaned with caution and for a short time. Ultrasonic cleaners are not recommended for cleaning large gemstones, gemstones with faults or indeed any of the following: emerald, turquoise, malachite, opal, pearl and coral.