Until about 20 years ago when someone would purchase a diamond, they would just go to someone they trusted and would buy from them. Usually, their jeweler was someone from their community or someone their family used for a while. Normally, the jeweler would not include a diamond appraisal in the purchase, unless specifically requested. Today, most jewelers include the appraisal even without asking. The diamond appraisal would include an approximate amount that the ring is worth and how much it can be replaced at.
A Diamond appraisal is normally requested by insurance companies, for them to know the value of the diamond you purchased. In most cases, diamonds appraise for more than the actual purchase price and that is because the diamond appraisal is based on MSRP and not the purchase price.
Not all diamond appraisals are accepted by insurance companies. It is advisable to make sure that the appraisal provided by your jeweler will be recognized by your insurance company. Also, you should make sure that specifications on which your purchase was for matches that what is stated on your appraisal. It can happen sometimes when an appraisal company can have a typo, so you should always double check before leaving your jeweler.
It isn’t recommended to buy from a jeweler if the appraisal is not recognized by the big insurance companies. You can also usually always verify it on the appraisal companies website to cross reference.
Another pointer in diamond appraisals is that not every jeweler will appraise the diamond for the same amount or the same specifications of the diamond. The reason for this is simply because a diamond does not have an absolute grading process in which all jewelers use, so there always will be a discrepancy, so this should not alarm you should you get different opinions. The main objective of the diamond appraisal is that the diamond will be insured and obviously look like what you ordered. Often people panic when they see that a different jeweler has graded or appraised their diamond differently than the original appraiser. This is something which you do not have to worry about and like I explained above is completely normal.