VTG Silvertone Crystal Drop Necklace After Thoughts Rhinestones Y2K 90's 2000's

This necklace is at least 20 years old. I think it was one of my prom options, 2001-2001 but it could be one I had before then. I loved After Thoughts. It's so sparkly! It does show signs of age, especially on the back/bottom but I'm sure someone who knows what they're doing could restore it to it's former glory with easy. I don't want to risk messing it up, because I don't know how. It measure 16" long, I often wore it with an extender.