Deanna Hamro Black Disco Ball Drop Clipon Earrings.  These sparkle and look amazing.  I'd say be careful with these because these tiny crystals are foil backed and are less than 1mm in size.  They are near impossible to find so if you lose any of these crystals it will be a bummer. 

Also I can almost see the use of glue (hardly see) so my guess is that it is something that happens. 

If you are a jewelery maker or good at jewelery period my suggestion would be coat them in glueand use rubbing alcoholic the surface crystals on a q tip to cleanse them and you probably would be better off than risk losing any crystals and them doing a hacked up glue job. Not just any glue....has to be jewelery kind. 

Just a suggestion!  Don't k ow if it's the correct one for those but .....I don't know any suggestions by professionals out there I'd love to hear em!  Message me your thoughts on the subject of increasing time without potentially losing crystals on these amazing earrings!