Hello G. Rajendran, To offer some solutions to your problem of stones
coming loose and falling out, it would be useful to know:
1. whether the stones are set in bezels (open or closed back) or prongs,
2. if there is any obvious damage (dents, twisted prongs, and such),
3. what metal (alloy) is used,
4. what stones tend to fall out, and
5. what type of jewelry (ring, pendant, earring, etc.) has this problem.
I would start by listing the faulty returns by type, stone,
mounting, etc. to see if there is a pattern. Then track those
pieces through production - casting, cleaning, setting, and
finishing the problem pieces. You may be able to pin point a
weakness that is not visible during your quality control check. This
is rather like being a detective. No doubt you are frustrated. I
hope we can help you find answers. Judy in Kansas, where the sounds
of thunder and raindrops are so beautiful right now.
Judy M. Willingham, R.S.
Biological and Agricultural Engineering
237 Seaton Hall
Kansas State University
Manhattan KS 66506