There is something undeniably timeless about a strand of pearls. Unlike flashing diamonds or deeply colored sapphires, pearls carry a soft, organic luster that has symbolized elegance for centuries.

But because they are born in nature differently than other gems, they require entirely different rules for care.

If you own an ultrasonic cleaner—like a compact home unit from Creworks—you already know how magical it is for making diamonds, gold, and platinum sparkle like new in just minutes. It is tempting to look at a dulling pearl necklace and think, “Hey, why not drop these in for a quick refresh?”

As specialists in cleaning technology, we are here to give you a definitive, friendly warning: No, you should never, under any circumstances, clean pearls in an ultrasonic cleaner.

Let’s break down the science of why this happens, and how you can safely clean your pearls instead.

The Science of Softness: Why Pearls and Ultrasonics Don’t Mix

To understand why ultrasonic waves are a pearl’s worst enemy, we have to look at how pearls are formed.

Diamonds and sapphires are tough minerals formed under intense heat and pressure deep within the earth. Pearls, however, are organic gemstones created inside living mollusks. When an irritant gets inside an oyster or mussel, the creature protects itself by coating the object in layers of a microscopic substance called nacre (mother-of-pearl).

This organic composition makes pearls uniquely vulnerable to the physics of ultrasonic cleaning:

Ultrasonic Wave (40kHz) ➔ Microscopic Cavitation Bubbles ➔ Intense Vibrational Energy ➔ Cracks & Flakes Soft Nacre Layers
  • The Mohs Hardness Scale: On a scale of 1 to 10, a diamond is a 10. A pearl sits at a fragile 2.5 to 4.5. They are incredibly soft and easily scratched.
  • Microscopic Cracking: Ultrasonic cleaners work by sending high-frequency sound waves through water, creating millions of microscopic bubbles that implode against a surface to blast dirt away. To a diamond, this is a gentle bath. To a pearl’s delicate, layered nacre, these rapid vibrations can cause microscopic fractures, leading the pearl to crack, pit, or lose its beautiful luster permanently.
  • Dissolving the Glue: Most pearl earrings, rings, and pendants are held in place by a tiny post and specialized jewelry cement. The intense vibrations of an ultrasonic tank will rapidly break down this adhesive, causing your pearls to fall out of their settings.
  • Thread Degradation: If your pearls are strung on a silk or nylon thread, the ultrasonic waves and water immersion will stretch, weaken, and rot the thread from the inside out, leading to an unexpected snap.

How to Safely Clean Your Pearls at Home

Because pearls are so delicate, the safest cleaning method is incredibly low-tech. In fact, the absolute best thing you can do for your pearls is simply to wear them. Your skin’s natural oils keep them hydrated and prevent them from drying out and cracking.

When they do need a wash to remove sweat, makeup, or perfume buildup, follow this gentle method instead:

1. The: Prevention.

Always apply your hairspray, perfume, makeup, and lotion before putting on your pearls. When you come home, take your pearls off first. This minimizes chemical exposure.

2. The Wipe Down: After every wear.

After taking off your pearls, gently wipe them down with a soft, clean, lint-free microfiber cloth. This removes surface skin oils before storing them away.

3. The Barely-Damp Bath: Deep clean (As needed).

If your pearls are visibly dirty, mix a bowl of lukewarm water with one drop of mild, non-detergent baby shampoo. Dip a clean makeup brush or soft cloth into the water, wring it out so it is barely damp, and gently wipe each pearl. Never submerge a pearl strand in water, as it stretches the thread.

4. Flat Air Dry:24 hours.

Lay the pearls completely flat on a dry towel. Do not hang them up to dry, as the wet thread will stretch under the weight of the pearls. Let them dry completely for 24 hours before wearing or storing them.

Keep the Ultrasonic for the “Heavy Lifters”

Don’t let your ultrasonic cleaner gather dust just because it can’t handle pearls! Your Creworks ultrasonic tank is still the ultimate champion for the rest of your jewelry box.

What to save your ultrasonic cleaner for:

  • Solid platinum, gold, and sterling silver bands.
  • Hard, untreated gemstones like diamonds, rubies, and sapphires.
  • Intricate metal watch bands (with the watch face kept out of the water).

When it comes to pearls, think old-school, gentle luxury. Treat them with a soft hand, keep them away from the high-tech sonic waves, and they will retain their radiant, classic glow for generations to come!