Ultrasonic cleaning for jewelry: What works, what doesn't
Ultrasonic cleaners are widely used in households and by jewelers. They clean jewelry quickly and thoroughly – but not every piece can withstand this intensive cleaning method. This guide explains which jewelry can be cleaned ultrasonically and which cannot.
How ultrasonic cleaning works
An ultrasonic cleaner generates high-frequency sound waves (typically 40–42 kHz) in a liquid. These waves create tiny cavitation bubbles which, when they collapse, release microscopic pressure waves. These pressure waves dislodge dirt, grease, and deposits from surfaces – even in areas that would be unreachable with a brush. The result: very deep and even cleaning in minutes.
What can be safely cleaned with ultrasound
- Stainless steel 316L: Completely safe. Ultrasound does not harm stainless steel.
- Titanium: Also safe.
- Hard real gold (585/750) without stones: Gold does not react with ultrasound. Pure gold rings and chains without stones: no problem.
- Hard gemstones without inclusions (diamond, ruby, sapphire): If the stones have no cracks or inclusions and are well set: generally ultrasonic-safe.
What should never go into the ultrasonic cleaner
- Pearls (natural and cultured): Ultrasound can shatter the nacre layers. Pearls will be permanently damaged. Never.
- Opal: Opals contain up to 20% water. Ultrasound can cause cracks and destroy the internal play of color. Never.
- Emeralds (treated): Most emeralds are treated with resin or oil. Ultrasound will dissolve this treatment. Never without prior confirmation that the stone is untreated.
- Gold-plated jewelry: Ultrasound can weaken the bond between the gold layer and the base material. Not recommended.
- Soft stones (Mohs below 7): Turquoise, moonstone, malachite, fluorite, hematite – all sensitive to ultrasound.
- Stones with cracks or inclusions: Ultrasound can enlarge existing cracks.
Gray areas: With caution
- Aquamarine: Usually ultrasonic-safe if no cracks – check for inclusions beforehand
- Amethyst and Citrine: Quartz is hard – if no crack is present, generally possible, but check
- Stones in prong settings: Ultrasound can further loosen loose prongs – check the condition of the setting beforehand
Household ultrasonic devices vs. professional devices
Inexpensive home ultrasonic devices (€20–60) have significantly less power than professional devices at a jeweler. This is good for simple everyday cleaning – for stubborn deposits or complex pieces, it's better to go to a professional.
Safely cleaned jewelry at Corelune Jewellery
Quality that's worth caring for – at Corelune Jewellery, you'll find pieces for which you can use these guide tips.
