A recent purchase, inheritance, or gift will spark the question, do I need a jewelry appraisal? The answer is a simple no. A jewelry appraisal is not a need, the same way you don't need a hammer if you are not building something. Now, you will need an appraisal if you want to insure your jewelry and it is recommended to have a fair market value appraisal if you want to sell your jewelry.
An insurance appraisal is needed the majority of the time when you want to insure your treasures. An insurance appraisal will most likely need to be done by a GIA Graduate Gemologist for your insurance to accept it. This document provides a full breakdown of your jewelry item; from diamond weight to metal purity to size to if the stones are natural or synthetic and so on. The appraisal will have all the information about your jewelry items, and the price of having to replace that item if lost, stolen, damaged, etc (depending on your insurance covering). It is a full replacement value of the item. This means that, if the item is fully covered, the insurance company will need to provide you the money to either, purchase the exact same item or recreate the item. This is why your item will need to be reviewed by a gemologist to make sure your item is correctly represented.
This is not a representation of what your item is worth if you would like to sell it. It is extraordinarily unlikely that your item can be sold for that price as it is a retail value. Many people use the insurance replacement value as a standard when they want to sell a piece to a jewelry store, which tends to create disappointment and anger on behalf of the seller. The insurance retail replacement value appraisal is strictly for insurance purposes in case the item needs to be replaced or remade.
A fair market value appraisal is a document that, once again, gives a full breakdown of your item. However, the dollar value associated with the appraisal is derived from a completely different thought process. The fair market value of a piece is what a customer can specific to receive if they were to sell it to a jewelry store (within a percentage range). This is a tool for the owner to understand their item better and what potential buyers may be able to offer for your jewelry. Again this is not set in stone, some jewelry stores will be more interested in your item as they have customers that enjoy those pieces and some can only offer a price that will ensure they can sell it for a profit. The fair market appraisal is a guide that will help you be an educated seller. The fair market value of an item will usually range from material value to wholesale value (jewelry dealers selling to other jewelry stores). It will usually be closer to the material value of an item.
To reiterate, you do not need a jewelry appraisal. There are reasons for needing one, insurance purposes or looking to be an educated seller, but it is not necessary for everyday life.