Short length of tightly woven herringbone-pattern chain in a dark, oxidized metal (likely brass or gold-filled base metal), fitted with rectangular gold-toned end caps at both terminals and a fold-over box clasp with a decorative shaped tongue at one end.
Too short to have functioned as a bracelet; the woven-chain-with-box-clasp construction is consistent either with a chain-link cuff fastener (a connector worn through a shirt cuff buttonhole in place of a link cufflink) or a fragment of a longer watch chain that has lost its T-bar/fob end. The rigid rectangular caps at both ends make the cuff-link reading more likely, since watch chains typically end in a swivel or spring-ring rather than a matched pair of caps.