Perhaps from chalao through the idea of hollowing out as a vessel (this metal being chiefly used for that purpose); copper (the substance, or some implement or coin made of it) -- brass, money.

see GREEK chalao

χαλκὸν (chalkon) − 3 Occurrences

χαλκὸς (chalkos) − 1 Occurrence

χαλκοῦ (chalkou) − 1 Occurrence