Ultrasonic cleaners use sound waves to break down the dirt particles accumulated on the surface of your jewelry. It is important to know what materials you can clean with these devices and which ones you should avoid as putting the wrong piece of jewelry in may damage it.
How Ultrasonic Cleaners Clean Your Jewelry
Ultrasonic cleaners remove dirt from jewelry by using ultrasound: The pieces are put in a cleaning liquid, and after the machine is turned on, it emits ultrasonic waves that create vibrations through the liquid, knocking dirt particles off the jewelry.
This cleaning process is pretty neat and efficient, but it is also the reason why your jewelry might come out of the cleaner with loosened stones.
Diamonds in an Ultrasonic Cleaner: Be Careful
Although diamonds are very durable stones, sometimes it may be risky to clean them in an ultrasonic cleaner. Diamonds that have significant inclusions are at risk of damage since the ultrasound vibrations can make these internal flaws worse.
The rule of thumb is that if a diamond has big and very visible inclusions, there is a higher risk of internal damage when using an ultrasonic cleaner, and that risk depends on the nature of the inclusion. Most diamonds sold as jewelry are not that badly included so as to be at risk, but you may want to err on the side of caution if the stone has very visible inclusions, and you may prefer to opt for professional cleaning in that case.
You might think that clarity-enhanced diamonds shouldn’t be at risk because you can’t see any internal flaws, but actually the opposite is true.
These stones’ clarity has been enhanced through fracture filling or laser drilling, and the process makes the diamond more likely to crack when cleaned with an ultrasonic device, so proceed carefully or take your stone to an experienced jeweler for cleaning.
Some colored diamonds also should not be put in ultrasonic cleaners. Many diamonds of this type have been treated to enhance their color, and depending on the treatment, ultrasonic cleaning can undo this effect to an extent, making these stones’ hues less vivid. So if a diamond’s color has been enhanced, don’t risk it unless you’re certain that the treatment effect will hold.
Here’s what the Gemological Institute of America has to say on ultrasonic cleaning and diamonds:
Proceed cautiously if the diamond contains feathers or is included, and avoid ultrasonics if the diamond has been treated by fracture filling.
Can I Clean Other Gemstones?
Generally, the more brittle the stone, the more likely it is to be damaged in an ultrasonic cleaner.
Emerald, onyx, opal, tanzanite, lapis lazuli and turquoise are all examples of stones that shouldn’t be cleaned with ultrasonic devices. These gemstones can be damaged in the cleaner by the heat or the vibrations.
In addition, many of them have been treated using heat and other methods to enhance their color, making them even more susceptible to damage.
Gemstones with cracks that have been filled with oil or other materials as well as stones whose surface has been coated with a polymer or other substances should also not be cleaned this way.
In general, most gemstones are not suitable for ultrasonic cleaning, and you shouldn’t risk putting them in the cleaner unless you are certain that they are durable enough and untreated (for example, untreated ruby). This is also true for most synthetic or fake gemstones.
Click here to see a gem cleaning kit that can be used on most gemstones. Don’t forget to read the label and instructions in order to make sure that the cleaner is safe to use with the jewelry you have.
Can You Clean Pearls in Ultrasonic Cleaners?
Pearls are very soft and ultrasonic cleaning may partly dissolve them. Whatever the pearl, never put it into an ultrasonic cleaner.
Only use warm, soapy water to clean pearls, and while we’re at it, never use alcohol or other chemicals on them.
What About Other Organic Gems?
If you’re wondering whether amber or coral can be put into an ultrasonic cleaner, the answer is “no.”
Just like most other gemstones, these gems can be easily damaged by ultrasonic cleaning.
Can I Put Metal In?
Generally, yes. However, a notable exception is tungsten. This metal should not be put in ultrasonic cleaners because the cleaning process can damage it.
Whatever metals your jewelry is composed of, make sure to ask your jeweler whether it is safe to clean it with an ultrasonic cleaner as you never know what metals or alloys make up your jewelry.
What Can I Clean Using Ultrasonic Cleaners?
Metals such as gold and platinum are safe to clean with ultrasonic devices.
Hard natural gemstones such as rubies can also be put in an ultrasonic cleaner provided that they have few and small inclusions and have not been treated with heat or chemicals, or don’t have any coating.
Even then, do not clean in such cleaners jewelry in which the stones touch (like in a channel setting, for example); otherwise, they might chip when subjected to vibrations.
Anyway, be sure to ask the jeweler at the time you purchase any piece of jewelry whether it can be cleaned with an ultrasonic cleaner. There might be unsuitable alloys or gems, or some gemstones may have been treated, becoming more vulnerable in the process.
You can also consult your local jeweler regarding any pieces that you already own but are unsure about. If in doubt, let a professional handle the cleaning.
How Ultrasonic Cleaners Can Loosen Your Gemstones
Since ultrasonic cleaning works through sound waves, they can cause a stone to vibrate in its mounting.
One cleaning session can be long enough to expose your jewelry to vibrations that could loosen its settings.
Sometimes, you may notice that some of the stones have come off while in the cleaner. Very often, you may not find out that your setting is loose until later, when your stone falls off.
When Are Your Stones More Likely to Loosen?
Usually, stones in settings that are old and worn are easier to loosen. If your prongs are worn thin or are bent, their grip is more likely to be weakened further by the cleaner.
Pay special attention to jewelry that is very dirty as sometimes dirt particles hide damaged mountings and help weak settings keep the gemstones in place.
When the dirt is cleaned off by the ultrasound, however, you may find that your stones are no longer held tight.
What You Should Do After Ultrasonic Cleaning
To make sure your gemstones are safe after they have been cleaned with ultrasonic waves, you should always check your jewelry after it is taken out of the cleaner.
If you’ve had your pieces cleaned by a jeweler at the shop, always ask the staff to inspect the pieces AFTER they are cleaned. Often, your rings and other jewelry won’t be checked thoroughly unless you request that explicitly.
If any of the pieces have become loose, it’s best to have them fixed and tightened while at the store.
If you are doing the cleaning at home, check all settings yourself. Look for stones that move in the mounting, even if only slightly; you never know when a gemstone may come off.
Check if any of the prongs are weakened or bent, and pay special attention to the ones that look thin and worn. Even if the setting doesn’t have prongs, it can still be loosened by the ultrasound.
If you spot any problems, you should have them corrected as soon as possible. Have any loose mountings fixed immediately, especially if you see worn or broken parts. You don’t want to risk losing your expensive gemstones.
Next: Browse this selection of ultrasonic cleaners and check out their prices, and don’t forget to read our article on using an ultrasonic cleaner.