These three pieces with .5" ferrotypes of Western Theatre generals c. 1862  were originally strung on cords to form a bracelet. We've also seen one for Grant. Each is 1-1/8" diameter made from a carved tagua nut (from a palm tree) also known as vegetable ivory. Each reverse has an as made small hole at the center plus four smaller holes on the side edges of the circular area to allow joining by cords. There are a few tiny surface hairline cracks on the reverses plus the delicate outer edge of each has one or two tiny missing flakes but so small as to be barely noticeable. As these come, condition is VF. Ferrotypes are NM. The ferrotype for Rosenkranz is a misspelling of Rosecrans.