Pretty mandolin pin of Florentine mosaic.
It is 1 3/4" long and has a pinback clasp. These pins have been a popular souvenir of Italy since the 1800's. The tesserae or tiles have gotten larger as fewer persons do this kind of detailed hand work. It is a dying art. When I first visited Italy in 1970, mosaic pins were everywhere, but last year they were harder to find and much more expensive.
This pin or brooch dates from the 1980's and is in excellent condition.