Top row, left: a mid-1800s to early-1900s ladies sash buckle or brooch - can't tell which, because all of its attachments are missing.
Top row, right: a Mosman's 1879 Patent civilian horseharness buckle-shield -- the photo below shows one with the patent-date stamped into its back... and the scan is from an 1895 Montgomery-Ward mailorder catalog's horse-equipment section (but it miss-spells Mosman as Morsman).
Bottom row, left: a tintype or daguerreotype or ambrotype (photo) frame, dating to the civil war era and several decades afterward.
Bottom row, right: various US Army regiment-number and company-letter hat insignia, dating from the civil war era into the Indian Wars era -- the size of yours indicates they are civil war era.