Greek telesma, from telein, to complete, fulfill, consecrate, named a religious rite, then a consecrated object. Arabic carried tilsam through the medieval world; the Picatrix and Hermetic manuals fixed the talisman as the astrologically timed, ritually charged device. Telos, the end or completion, is the same root that gives teleology.
The demotic survival: rabbits' feet, evil-eye beads, medallions, the talisman democratized into every kiosk. The charging ritual dropped out of the product line; the confidence stayed in.
The root's logic: a talisman is an object with its telos installed, matter given an assignment. Consecration as commissioning: the rite does not add power, it adds purpose, and the distinction between a pebble and a talisman is paperwork.
When does an object stop being a thing and start being a battery?