A bit of a random one here but I have come across some of my grandma's pearls, I've been searching online to see if they are worth anything (I don't want to sell I just want knowledge on them) I was 7 when she passed away 20 years ago so I believe they are at least 30 years old. When looking online I can see some are worth thousands and others nothing. Can anyone tell me anything about these. They are pristine.