cleaning very old dirty diamond rings

[Acquisitor]

I have received a few very gold gold rings with diamonds. However these rings havent been cleaned for ages, if ever.

the diamonds are cemented into some very white looking hard substance.

My ultrasonic cleaner cant handle this, I tried to cook the rings in water and yet it doesnt get the job done.

A question for professionals: whats the most aggressive liquid out there to be used in ultrasonic cleaner that can clear the debris?

Without of course damaging gold and diamonds.

please help

 

[Circe]

You don't actually need the ultrasonic at this stage. Drop them in some plain old rubbing alcohol, leave them overnight, and then try scrubbing them gently with a very soft brush (baby tooth brushes work fairly well). That should loosen enough of the crud to let the ultrasonic do its job on whatever is left.

 

[chrono]

Soak them overnight in hot soapy water then brush out the softened crud with a baby toothbrush. You will probably need to do this for several days until the worst of the dirt is gone.

 

[iluvshinythings]

You could try soaking them in vinegar. I don't know if it's safe enough to do very often but I've done it and had good results. I'd try soaking them in soapy water a few times first.