I was under the impression for a ture appraisal for at least gemstones you will need a AGL report (industry standard). Without a report an appraiser will have no idea of the gemstones are heated/ treated etc. And of course treatment will be one of the leading factors in appraisal worth.
I would hit the report button and move this to the CS forum for more info. I dont' have a clue about pearls, but for CS I believe that is the way forward. Once again I would still see what the experts say.