A tiny masterpiece, portrait miniature of top quality. Dating 18th century, powdered hair and elegant elaborate clothing to include an embroidery trimmed yellow silk vest, and blue top coat. I can see what I think is a signature, but it's just impossible to make out, along the edge right of his shoulder. Exceptional work of art, a most expressive face - definitely the work of a Master. He seems almost to be of the Incroyables et Merveilleuses of c.1785-1799, but I do believe his earlier by a generation, Louis XV to XVI era. Full measurements noted on the photos.
Very good to excellent condition, no warp nor damage to the old painting. Backed by an old card, it is in a brass or perhaps gold faced mount which would have once been center to a wooden French frame. Like many, it wood outer frame has been removed over time, to the tastes of collectors. From "a gentleman's collection", it is a small masterpiece, still elegant and retains the convex cover glass.