I understand that this would seem to be a simple enough request. We're in the jewelry business and deal with theses things, all day every day. Unfortunately, it's not so easy, here's the questions that need to be answered:
1. If you have diamonds, what are the qualities?
Trying to determine the various qualities of any kind of stone set in prongs (which get reflected/ refracted throughout the stone) is difficult. At the very least, the stones should be thoroughly cleaned and studied under ideal lighting. This takes time and should be part of a formal appraisal.
2. Are the stones genuine, natural, lab created or created?
These days it takes some sophisticated equipment to be certain you're separating the lab grown from the natural gemstones as they are made using the same exact minerals and chemistry that is found in natural stones.
3. How badly worn the piece is and if (and how much) work needs to be done?
While, generally, this is not a problem, as we do this all day long. However, there are exceptions.
4. What do you mean by worth?
Are you asking for a replacement value, how much we would pay you for it or how much you should ask for it? These will, very likely, be 3 entirely different prices.
5. Why are you asking us this?
In years past, we've tried to be helpful and offered general prices for people, only to find that we put ourselves in the middle of a dispute between buyer and seller.
We're sure you can understand, we prefer not to get into arguments and to avoid any potential for liability.