The Hemiobol denomination
An ancient Greek silver coin denomination with a value of 1/2 obol, or 1/12 drachm. Generally it weighs around 0,36 grams.

In Ptolemaic egypt, it was also struck in bronze.
Hemiobol

(1) Ptolemy II 264-256 BC
Obverse: head of Zeus-Ammon right with tainia
Reverse: eagle with spread wings standing on lightning; ΠΤΟΛEMAIOY ΒΑΣΙΛΕΩΣ, Θ between eagle's legs
Ref: Svoronos, 469
(2) Ptolemy III 246-222 BC
Obverse: Diademed head of Zeus-Ammon right, wearing tainia.
Reverse: Cult statue of Aphrodite Cypria standing facing on pediment.
Ref: Svoronos 1007; Weiser 109; SNG Cope...