Found with other pictures from Marion County
This a Gem tintypes were the smallest made - measuring about 1/2 x 1" or slightly larger - but nonetheless often an astonishing amount of detail is visible. They had popularity throughout the 1860s, peaking about in the mid decade. Occasionally they are seen from much later in the 1800s. "Gem" sized tintype approx 5/8 x 1", slightly larger than the visible portion, which is a oval 1/2 x 13/16".