Here is a similar coin. If you could provide the dimensions (e.g. 22mm) that would
help people who know this
type.
Several rulers minted coins that look similar (at least it appears that way from my brief
search). It is probably 4th century AD but you can definitely get a more concrete
identification.
As for the grade, I wouldn't know enough to say
Superb, but definitely in the range of
Good VF-EF at the very least, IMO. Also, I don't know about authenticity so perhaps someone else could weigh in.
INDIA,
Kushan Empire. Shaka. Circa AD 325-345. AV Dinar (20mm, 7.61 g, 12h). Shaka standing facing,
head left, sacrificing over
altar and holding
standard; filleted trident to left / Ardoxsho seated facing, holding filleted investiture garland and
cornucopia; tamgha to upper left. MK 591.