Jewelry Designer - Create Indented Surface for Inserting Diamonds on STL Model

Transform surface of STL model by creating indentations/cavities in which to insert brilliant cut diamonds/stones. This will be a pendant for a necklace. A jewelry designer should be familiar with the proportions of brilliant cut stones and design accordingly. If not, there are standard size CAD files and proportions available online.

The final goal is to 3d print this item and manually glue gems into the cavities. This reduces manual labor.