6. What is the difference between a grading report and an appraisal?
A grading report, or quality analysis, provides gemological information only (quality and proportions). It does not provide a valuation. Labs such as that of The Gemological Institute of America (GIA) or European Gem Lab provide these kinds of reports.
An appraisal includes description of quality and proportion, as well as a value appropriate to the particular assignments purpose. (See question #1.)