18 different cuts of gems (with diamond dispersion shader) that I have created to get better with lighting and dispersion of light and then I decided that I will sell them.
(Avaible to download for free) https://www.blenderkit.com/r/mikocg
https://www.cgtrader.com/3d-models/various/various-models/pack-of-18-gem-cuts-for-jewelry
https://www.turbosquid.com/FullPreview/2145486
Video with all cuts