There is not much detail around that area, but based on the angle and placement of the gold, I'm pretty confident it's a knife. Housed in its full original case, 3.75" x 3.25" when closed.
Ambrotype is behind glass an in very good condition overall. The covers of the case are separated along the spine. Soldier rare photograph tin type antique photo photography marine navy naval picture history historic 1860s uniform nbsp. The item "Civil War Navy Sailor Armed with Knife 1860s Photo Confederate or Union" is in sale since Saturday, February 24, 2018.
This item is in the category "Collectibles\Photographic Images\Vintage & Antique (Pre-1940)\Ambrotypes". The seller is "jack_mord" and is located in Woodinville, Washington. This item can be shipped to United States.