I used to wear an amulet, and when I have exams or anything I carry a small chinese stone and coin in a silk pouch that my mum bought me for luck. I don't know if they worked. I always without fail wear my silver chain with two silver hearts looped on it, my boyfriend bought me them as earings 2 and a half years ago but one broke the day I got them so I broke the other one and put them on a chain and they look beautiful. I don't think any random piece of jewelery can help, but when you have something that was given with love and it's something you really care about it can give you confidence. I play with it when I'm nervous and it just reminds me that I'm not alone, and it inspires me. Sounds a bit silly but it's become a part of me now, and it's comforting to have it. I think it's kinda the same as people wearing their parent's wedding rings ect.
Also, if you buy something like an amulet you have to be careful when you choose it and make sure it feels 'right' with you, and then meditate with it, or just carry it around and make it 'yours', that's the wiccan idea of having stones ect, I'm not sure if the reiki way is different.
Just my random thoughts anyway :lol: