LSJ
η, ον, of bronze, νόμισμα OGI 339.44 (Sestos, ii BC); διάδημα Ostr. Bodl. i 262 (ii BC); χαλκίνη (sc. δραχμή) PLond. 2.380 (ii/iii AD).
concerning or in bronze coin, λόγος PTeb. 119.51 (ii BC).
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)