The Hemidrachm denomination - Variants: Triobol
The Hemidrachm was an ancient Greek coin denomination with a value of 3 obols, which is half a drachm. it is also often called a triobol.

The hemidrachm generally weighs around 2.15 grams when struck in silver, but was also struck in bronze.
Hemidrachm|Triobol

(1) Achaean League c. 86 BC
Obverse: head of laureate Zeus right
Reverse: fish under (AX) monogram all within wreath; (APT) left / ΔY up
Ref: Clerk 55; BCD Peloponnesos 482
(2) Achaean League 160-146 BC
Obverse: laureate head of Zeus right
Reverse: (AX) monogram, thunderbolt below, all within wreath; ΞB / K_A / M
Ref: Benner 17; BCD Peloponnesos 1551.1;...
(3) Achaean League c. 188-180 BC
Obverse: laureate head of Zeus right
Reverse: (AX) monogram within wreath; A_N / CΩ
Ref: Benner 5; BCD Peloponnesos 1492.2; ...
(4) Achaean League c. 175-168 BC
Obverse: laureate head of Zeus Amarios right
Reverse: lyre above (AX) monogram, all within wreath; ΔΩ_PO
Ref: BCD Peloponessos 27.1; McClean 6431...
(5) Achaean League 100-80 BC
Obverse: laureate head of Zeus right
Reverse: (AX) monogram, trident below, all within wreath; A / Π_Λ / (YE)
Ref: BCD Peloponnesos 1593.2; Benner 4; ...
(6) Apollonia Pontica c. 350-300 BC
Obverse: facing head of Medusa
Reverse: anchor flukes up; A / crayfish
Ref: Apollonia p. 347, 1; SNG BM Black S...
(7) Byzantion 387-340 BC
Obverse: forepart of cow left, below dolphin swimming left; (BY)
Reverse: wide ornamented trident
Ref: Schönert-Geiss Byzantion 778; SNG B...
(8) Cherronesos (Thrace) 400-350 BC
Obverse: forepart of lion right, head turned back
Reverse: quatripartite incuse square, grain ear in one section, X· in other
Ref: McClean 4103 var (dot over E)
(9) Neapolis (Macedonia) c. 424-350 BC
Obverse: facing head of Medusa (Gorgoneion), tongue protruding
Reverse: diademed female head right; NEOΠ
Ref: SNG ANS 430-454; SNG Cop 227; SNG B...
(10) Odrysian Kingdom Odrysian Kingdom | Parion imitative 500-350 BC
Obverse: head of Medusa (Gorgoneion) facing
Reverse: incuse square with cross and pellet
Ref: cf.SNG France 1347; cf.SNG Copenhag...
(11) Olympia 312-271 BC
Obverse: laureate head of Zeus right
Reverse: eagle right; olive leaf right; F _ A
Ref: BMC 84. Dewing 1896. McClean 6637. ...
(12) Parion c. 350-300 BC
Obverse: head of Medusa facing (Gorgoneion)
Reverse: bull standing left, head turned right; dolphin above; Π_A / PI
Ref: BMC 22
(13) Pharsalos c. 450-400 BC
Obverse: helmeted head of Athena right
Reverse: head of horse right; Φ A / P Σ
Ref: Lavva 75 (V38/R44)
(14) Phasis? c. 425-325 BC
Obverse: Archaic female head (Artemis Dali) right
Reverse: Head of bull right
Ref: SNG BM 1013-1018; Hind 7; HGC 7, 21...
(15) Sikyon c. 330-280 BC
Obverse: Chimera walking left; ΣI
Reverse: dove flying left, •
Ref: BCD Peloponnesos 292; SNG Cop 64; B...
(16) Tanagra 457-448 BC
Obverse: Boeotian shield
Reverse: forepart of horse right within incuse square; T_A
Ref: Dewing 1498 (same rev. die)
(17) Teos c. 500-460 BC
Obverse: Griffin seated right
Reverse: rough incuse square
Ref: Balcer group XXI, 51-6; SNG Copenha...
(18) Thebes 426-395 BC
Obverse: Boeotian shield
Reverse: Kantharos; club above; Θ_EB
Ref: BMC 64; SNG Cop. 289
(19) Trikka c. 480-400 BC
Obverse: naked Thessalian youth standing right, restraining forepart of unruly bull prancing right
Reverse: forepart of bridled horse prancing right, within incuse square TPI_KK_AI (retrograde)
Ref: SNG Oxford 3933; BCD Thessaly II 76...