The Trichalkon denomination
The trichalkon was an ancient Greek bronze denomination worth 3 chalkoi.

Since the numbe of chalkons to an obol varied across regions a general weight is impossible to define, except that it weighed three chalkoi from the region it was struck in..
Trichalkon
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An AE Trichalkon struck 351-347 BC in Daulis?
Obverse: three filleted boukrania; ΦΩ_ΚΕ_ΩΝ

Reverse: laureate wreath; T

Diameter: 21 mm
Die Orientation: -
Weight: 8.9 g
time of Palaikos
Slg. BCD Lokris - Phokis 328; SNG Copenhagen 125; BCD Lokris 328-31; HGC 5, 1099.