Penannular gaps, snake heads, and twisted wire around the wrist.
Bracelets divide by construction: solid bangles (closed ring), penannular forms (open with a gap, often with decorated terminals), and flexible types of twisted or plaited wire. Bronze Age arm-rings can be massive gold; Iron Age and Roman examples run to snake-headed terminals, cable twists, and glass bangles (a distinct Romano-British favourite).
Terminals carry the identity: animal heads, expanded trumpets, stamped ring-and-dot. Viking-age arm-rings of standardised weight doubled as currency — look for nicks where silver was tested. Shale and jet bangles turn up as glossy black rings, often broken into arcs that get mistaken for something industrial.
Measure internal diameter (child, woman, man?), section shape, and weight — weight especially for precious metal, where currency standards may apply. Describe terminals closely; they are usually the datable part.
Identifying brooch and fibula types