Coin is:
MAXIMINUS II AE23mm 4.2g Follis (F, patina, traces of cleaning)
OBV: IMP C GAL VAL MAXIMINVS PF INV AVG; laureate head r.
REV: IOVI CONSER – VATORI AVGG; Jupiter standing facing, looking l. chlamys hanging from l. shoulder, r. holding globe, l. leaning on sceptre. Wreath in left field and Γ in right field.
EXE: SMHT, Heraclea mint.
REV: RIC VI Heraclea 69var, unlisted for officina Γ. 312AD.
It's an interesting coin of a rather scarce INV issue of 312. NOT IN RIC has also a few examples:
http://www.notinric.lechstepniewski.info/6her69a_g.html