how can I authenticate my "mikimoto" pearls?

by sandra h.
(grand prairie, texas)

I was given a set of pearls as an 18th birthday gift, my mother telling me they were Mikimoto pearls. Now decades later, I can't find the box and so have no way to really know if her statement was true. I'm afraid to leave them anywhere as I've heard the good ones sometimes are swapped for look-alike less value ones. They were bought in the 60s and are unknotted graduated with a gold filigree clasp. I can take a photo if needed.