When buying diamonds in a mounting, grading takes a lot of skill and some courage. If the diamonds are not completely clean, the task is almost impossible.
First let the ultrasonic cleaner do its work using a water- detergent solution mixture. The ultrasonic cleaners
with heaters are preferred for speedier dirt removal. Be sure you let the jewelry vibrate in the cleaner for one minute to several minutes, depending on the amount of grime involved. Here is where most of the dirt is actually loosened or removed.
The steamer looks very impressive in action, but again the ultrasonic cleaner does the hard work.
There are special tongs available to hold rings in the steam to avoid getting scalded. When steaming, try to concentrate the stream on the pavilion of the diamonds, where a lot of the grunge will collect and hide.