The Hemitetartemorion denomination
The hemitetartemorion is a tiny Greek denomination worth half a tetartemorion - equivalent to 1/8th of an obol.

It weighs 0.09 grammes, and usually measures 3-5mm in diameter.

It was the smallest Greek denomination, and was equivalent to 1/48th of a days wage. It was very infrequently struck.
Hemitetartemorion
(1) Erythrai
/Files/Images/Coinsite/CoinDB/Hemitetartemorion_Ionia.jpg
An AR Hemitetartemorion struck 520-480 BC in Erythrai
Obverse: Rosette or floral pattern with central pellet

Reverse: Five pellets within cruciform incuse

Diameter: 3 mm
Die Orientation: -
Weight: 0.09 g
This is only provisionally attributed to Erythrai by SNG Kayhan (740), whereas SNG von Aulock classifies it as 'Uncertain Ionia'.
SNG Kayhan 740 (Erythrai?); SNG von Aulock 1807 (Uncertain Ionia)
/Files/Images/Coinsite/CoinDB/Milet-Eritreia_tetartemorion.jpg
An AR Hemitetartemorion struck c. 520-480 BC in Miletos | Erythrai
Obverse: rosette with central pellet

Reverse: incuse quadrilobe, Stellate pattern of five pellets

Diameter: -
Die Orientation: -
Weight: -
No notes for this coin
SNG Kayhan 740; Klein 433.