Ultrasounds may be very effective for cleaning jewelry and provide results that can hardly be achieved with any other means but not all jewels are suited for ultrasonic cleaning. Considering the large variety of materials and shapes it would be best to ask advices to the jeweler at the time of purchase.
Jewels should live in the spotlight, they have to shine in their whole life but jewels tend to accompany our life and the life of our families.
Small errors in the cleaning process may add over time therefore it becomes very important to take care of your jewels in the appropriate way.

Ultrasonic cleaning is most suited for metal jewels and it must be avoided for emeralds, lapis, malachites, opals, tanzines, turquoise, organic gems such as amber, corals and pearls. Furthermore some gems are resin-impregnated or "oiled" to cover micro-fractures and make the gem shine more. Not only cleaning with ultrasounds these kind of gems may result in the opposite effect of making them opaque but also crack and ruin them.
Emeralds and similar hard stones, could actually be cleaned with ultrasounds but just if you'd be sure they are defect free, with no flaws nor fissures. Said that, it is better not to risk.

Considering that dust frequently contains quartz that is a quite hard material, it is good pratice to rinse your jewels before any cleaning process.

Non porous, non organic stones can be cleaned with SONICA UG or regular soap, most of the times ultrasonic cleaning in clean water will suffice.

It is better to avoid sudden changes of temperature when cleaning gems, and considering that ultrasounds will do most of the cleaning work, avoid high temperatures.

When choosing an ultrasonic cleaners for cleaning your jewels, chose high frequency ultrasonic cleaners, in the range of 40KHz-45KHz since lower frequencies may damage your gems.

While ultrasonic cleaning is a perfect way to clean in the interstices between the setting and the gems delicate settings may not be suited to ultrasonic cleaning.
Infact ultrasonic cleaners are used by professionals to test if the stone is firmly placed in the setting. If you're not sure if your setting is suited for ultrasonic cleaning, ask your jeweler.

The cleaning process is quite stright forward, economic and fast:

• rinse your jewelry in water
• fill the tank with water and if suited with a bit of SONICA UG (dilution 5% - 8%) or soap
  prefer demineralized water
• set the temperature around 30C if you're cleaning jewels with gems or at 60 C if you're cleaning metal jewelry heating the water will make the process faster at the cost of longer initial setup (ultrasonic cleaners with heater are more suited for professional use)
• if you're using a metal basket place a sheet of plastic between your jewelry and the basket or use a plastic basket
• put the basket in the tank and turn on the ultrasounds for 3 to 5 minutes.
• dry with hot air or soft tissue