Zinc locations 13.5 rejuvenation(pls answer if anyone knows)

[Frankiekao]

I have trouble finding Zinc. Is it only buyable in the Somnium Mall? and if so, where do I get Stamps? I don't have enough

[Pika572]

You can get a stamp from fighting Neptune underwater on route 6

[Blontary]

https://bigjra.github.io/rejuv.html

 

You'll find locations for the various stamps in this walkthrough. It's not updated to v 13.5 though, so some may have changed

[Asnaeb]

If I understand how it works right, kecleon shop sells it on Mondays.