I feel like calling it an amulet implies its something weird or magic. If its just a normal necklace, why call it an amulet? And why freak out over losing it?
I call it an amulet because that's what the trainer who gave it to me called it. It's a long story.
Basically, when I was eleven (before I started my very brief journey as a pokemon trainer, so before I had Jasper) my family took me on a trip to Lavender Town. I don't remember why we were there exactly, something about needing to be familiar with the region before setting off on my journey so I don't get lost.
The problem was, my parents were much more focused on my one year old brother to really pay attention to me. I got bored and wandered off into the surrounding forest (yes, child me had awful survival skills). That was where I ran into a Hypno.
Okay, so the next part is a little fuzzy, for obvious reasons. Next thing I know though, I'm in the woods, and the hypno is getting absolutely wailed on by a gengar. Its trainer, this nice older lady in a purple dress, helped me up, gave me a blanket (it was late at night at this point and pretty cold), and then handed me a necklace with a silver pendant in the shape of a ghost.
She said it was some kind of amulet that would protect me. She also said that the hypno was attracted to me because I was "gifted".
Truthfully I was still like half asleep at this point so I might have missed some details there, or maybe the lady was just speaking nonsense, who knows.
Anyway, she recalled her gengar, the hypno ran off, and the nice lady walked me back to town where my parents, of course, tore me a new one for wandering off.
I've just kinda always worn the necklace since then. I never leave home without it. I don't think it's actually magic or anything, I think really she was probably just trying to comfort me because I was a scared child.
Never did have anymore unfortunate run-ins with hypno though, so that's cool.