You have done your own checks. You still have unanswered questions.
Take it to a professional.
"Would the answer actually change what I do with this piece?"
Choose the right professional for your question: gemologist for stones, antique specialist for maker and period, appraiser for value. Get a cost estimate before committing.
When the identification would change what you do and the piece has characteristics suggesting value justifies the cost. For a common piece, it adds nothing.
Verbal assessment may be free. Written report: fifty to two hundred dollars. Lab report: one to five hundred. Match the cost to the piece.