What is the speed of light in a sample of fused quartz if the wavelength of the light being transmitted is 550 nm?
A hammer and chisel should do the trick. Or just keep the thing in one piece. It might be worth more.
The gemologist with over 40 years experience knows what he is saying. I have had jewelry valued for insurance purposes and they do considerably overvalue the items. Perhaps it is to protect you for future replacement costs. I have purchased several pieces of jewelry and had friends in the industry both as retailers and buyers of estate items. Everyone of them needed to look at stones with their special eyepiece (I forgot the name of it) in order to tell clarity, color, stability (cracked or not) and how much is actually able to be faceted. This exam can only be done in person and will tell the true value of each stone individually. If you aren't satisfied with one gemologist's estimate, you can always take it to another though it will cost for each specialists' appraisal. If you aren't sure who to ask, look for people wearing good jewelry when out and about and ask who they use. Ask several and use the one whose name comes up the most often. Also, don't be afraid to go to the top jewelry store in your area. When you go in, expect good and fair service and not bad advise. You will usually get what you project by your behavior and body language. He may not purchase your stones but he may know an honest private dealer he can refer you to. I do not know your circumstances but dress your best to be treated respectfully. Look businesslike and you will be treated in a business-like manner. A brillant jeweler will not judge you by your attire, but a very good one might. Just to be on the safe side, take close up photos of all of your stones separately and one of the group together. Should anything strange happen, between your list and the photos, you will have proof of your items. If your items have been worn, they may be worth considerably less than you might hope since wearing them diminishes their brillance and can damage their facets in a way that cannot be easily seen with the naked eye. Hope this helps.
Keep it in one piece if possible. A hammer and chisel is the easiest method. A diamond saw or aluminum carbide(sapphire) cut off wheel will cut quartz, though you then need a power source and some sort of coolant for the blade. Crystals are usually more valuable and attractive with a bit of matrix to serve as a base.