I am a bead seller and have many old beads that i have to research. I do my best researching with books,online information and consulting with other sellers. Occasionally I'll get a polite correction from a knowledgeable person and i'm extremely appreciative. I'll follow up to confirm what I've been told. I'll send him;/her a thank you. I could do without the snide arrogant corrections. fortunately they're infrequent