I'm sure this was salvaged or separated from a charming mid-1800s Palais Royal vanity set in pretty box, probably one with a couple of scent bottles and perhaps pearl handled vanity tools or sewing tools. A miniature, sweet to tuck into purse, or display on a doll's furniture vanity, perhaps. Doll collectors, alert! The generous cartouche on back is 18k gold, and the mirror is original and unbroken. It is a petit 3 1/4" in length. Full measurements noted on the photos.
Very good to excellent condition fora ge and type, I see no flaws to note. Acid tested 18k gold cartouche which has not yet been monogrammed.