Actually no correct judgement is possible by these and only these pictures.
Not entirely so...How many Athens gold issues do you know of?
The most probable conclusion re the second coin is thus ....?
Some history on the only Athens AV issues ..Suffering from a lack of funds late in the Peloponnesian War, Athens struck its first gold coinage, a clear sign of an economic emergency and one documented in the annual Parthenon inventories. In 413 BC, the Spartans captured Dekeleia and thereby cut off Athens from its main silver source at Laurion. By 407/6 BC, the need to raise funds for the city's defense became so desperate that the authorities ordered the melting down of available gold, including seven gold statues of Nike, which subsequently disappear from the inventory. The gold from this, comprising 14 talents, was then struck in six denominations, from staters to hemiobols. Once these coins were struck, the dies were then deposited in an alabaster box in the Parthenon treasury to ensure that they could not be misused (IG II 2.2, 665).
Virtually all known examples of the emergency issue of gold coinage
are in museum collections
... one of the rare exceptions exceptions below (one of five Athenian AV diobols known)... stylistically this is much later than the owl of the coin above... another pointer to fakery as the style of the owl is only to be found on silver issues of the earlier fifth century in which no gold coinage
was ever issued by Athens... without doubt it is a fake!
For more on the history of the coinage of Athens this is a nice summary http://www.eie.gr/archaeologia/En/chapter_more_7.aspx
As for the others the pictures preclude an exact match to material in Fakes database but they look suspiciously familiar to some listed fakes I have seen... the reverses of coins 1,3 & 4 plus the obverses of 2 and 5 would help in establishing the match to known fakes.....
Comment: I have to say that I cannot understand why anyone remotely familiar with numismatics posts one side of a coin in a grubby plastic flip with the genuine intent of seeking a view on authenticity. As for the provenance of these probable fakes... where have I heard this story before?
Edit: I am not even sure that these coins are gold .... based on the photos more likely some golden colored alloy, particularly the last one.