From my 'beautiful bits bin', this is a string of 4" long 19th century micro mosaic plaques, strung together with brass links in what would appear to have been perhaps a pocket watch chain or fob. Now, it begs some jewelry maker to incorporate the bits into something spectacular, doesn't it? Full measurements noted on photos.
Very good condition, such as it is. An incomplete pocket watch fob? A collected group of parts? Each is a brass basin plaque in the Etruscan manner, without any loss to the tiny colored glass tesserae. Display worthy just as it is. The red box is a photo prop and is not included.