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An ultrasonic cleaner is a device that makes use of cavitation bubbles to agitate and remove dirt and grime from different objects. It uses the ultrasound frequency (usually 20 – 40 kHz) to generate the cavitation bubbles. These devices are often hailed as an excellent way to clean objects like ornaments, jewelry, and even surgical instruments without the need for harsh solvents. While plain water can be used, ultrasonic cleaners work best with special cleaning solutions that amplify its effectiveness.

BUT there are some delicate jewelry and gemstone that are not suggested to be cleaned in this way. Here we will further discuss on this topic.

How Does an Ultrasonic Cleaner Work?

Ultrasonic cleaners are used for cleaning various kinds of surfaces, from jewelry to industrial tools and even medical tools. Larger ones can be used on golf clubs, components of firearms, and even fuel injectors. This type of machine is used extensively by professional restoration experts who need machines for cleaning rust and other types of grime from old items.

Watchmakers and jewelers will likely have at least one professional-grade ultrasonic cleaner in their workshops for cleaning jewelry and tools. The diversity of use of ultrasonic cleaners makes it one of the best cleaning methods around today.

Recently there are also compact size ultrasonic cleaner for household use. They focus on cleaning daily accessories like glasses, watches, portable smartphones, rings or bracelets accesories. Before using it for your personal items. You must understand what can it be used, and also what MUST NOT be put inside the cleaner. Otherwise, your delicate valuables might be damaged by the ultrasound.

What Must Not be Put in an Ultrasonic Cleaner?

Ultrasonic cleaners are incredibly efficient, but it is not a universal cleaner. Some materials may become damaged if you expose them to ultrasonic vibrations.

Flawed Gemstone Jewelry

A good example of such a material are gemstones with surface breakages or cracks that have been filled with wax and other filling materials. Some jewelers also use the first derivative to fill cracks in gemstones. These filled gems are likely to crack if exposed to ultrasonic vibrations. Even the hardest gemstone – Diamond. If there are some internal flaws, you may risk damaging the structure.

Additional materials used for filling are oils and resin. While filled gems look beautiful, we bring into question their durability, which is problematic because the materials used for filling are not as tough as the gem itself.

Organic, Semi-precious Stones

Next in line are organic gems. Organic gems are not mineralized structures, but they are considered precious formations all the same. Pearls, ivory, coral, jet, amber, and shell cameos belong to the category of organic gems. Many of them are unable to tolerate repeated exposure to water, and they’re not as durable as mineral gems, so you may end up damaging them instead of just cleaning them.

List of gemstones that are not recommended to be cleaned by ultrasonic cleaners:

  • Pearls
  • Turquoise
  • Coral
  • Emeralds
  • Jet
  • Amber
  • Shells
ultrasonic cleaner

Some organic gemstones are not recommended to be cleaned by an ultrasonic cleaning machine.

Wax Coated Gems

Third, are gems that have either been impregnated with a waxy substance or coated with them. These cannot be cleaned ultrasonically for the same reason that we can’t load filled gems.

Heat-treated Gems

Fourth are gems that have been heat-treated before being set into jewelry. The machine may end up damaging the coloration produced by heat treatment. Heat-treated gems are also more fragile and more prone to breakage. And finally, we have gems that are sensitive to changes in temperatures. Among these gems are zircon, lapis lazuli, opal, malachite, tanzanite, feldspar, iolite, and fluorite.

When loading jewelry onto an ultrasonic cleaner, it would be best to ensure that the gems are properly set (that they are not loose), so you will have no potential issues after cleaning. We don’t want a scenario where the machine’s excessive vibrations will cause the gems to fall off their mountings.

List of gemstones that are not recommended to be cleaned by ultrasonic cleaners:

  • Zircon
  • Lapis lazuli
  • Opal
  • Malachite
  • Tanzanite
  • Feldspar
  • Iolite
  • Fluorite
opal pearl ultrasonic cleaner

Opal and Pearls are examples that some organic gemstones are not suitable to be cleaned by ultrasonic cleaners.

What Liquid Is Used in Ultrasonic Cleaner?

Many kinds of ultrasonic cleaners are fit for specific kinds of objects and cleaning jobs. We’ll be outlining the most commonly used ones today.

Acidic cleaning solution

These are the solutions that have a pH of five or below. Use acidic solutions to scrub away at lime stains or deposits, scale, mineral traces, and rusting from different kinds of metals. This is generally recommended for general metal applications. Take note that this is not a good choice for metals that easily react with acids as your items may become damaged in the process. Cleaner tanks that do not have anti-corrosive linings are not a good option for acidic solutions as well. We recommend a tank-less setup instead if you wish to use highly acidic solutions.

Alkaline cleaning solution

Alkaline cleaning solutions are the direct opposite of acidic solutions. This type of solution is perfect for items made of stainless steel, tin, cast iron, zinc, brass, and steel. In short, it is ideal for general washing and cleaning of most items like jewelry. Additionally, it can be used safely on items made of glass, plastic, polymers, and ceramics as they will not damage these materials.

Enzymatic cleaning solutions

This type of solution is best used for cleaning items in the food and medical industries. This type of solution is formulated to deal with grime and other contaminants that are generally protein-based. This is the level one cleaning solution for materials like stainless steel, titanium, glass, plastics, titanium, and brass.

High caustic cleaning solutions

If enzymatic cleaning solutions don’t work, this is level two. Great caustic solutions make easy work of thick wax, fats, oils, and other kinds of oil and great that stick powerfully to materials like stainless steel and cast iron. You can also successfully use this on steel.

Neutral cleaning solutions

Neutral cleaning solutions are best for removing pigments and basic dust and greats from rubbers and plastic. Sometimes this is also used for glass and metals. It is capable of removing organic compounds as well. An ideal solution for clearing precious metals like gold and silver, plus ceramics and different kinds of jewelry, including costume jewelry. An excellent solution that is not corrosive and will not damage precious metals.

De-ionized water

This is even safer and more neutral than neutral cleaning solutions. It can be safely used for various materials, including most metals, rubber, fabrics, glass, and plastics.

Specialized solutions

Use specialized solutions if you need to remove waxes, soot, resin, and some superficial damage due to smoke. This can be used adequately for equipment used by first-responders. If you need to clean the components of firearms, you can use it as well.

Ultrasonic cleaner jewelry not suitable list

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