Ancient Greek coin. [opgelost]

Cheers

I have what may be a ancient Greek coin but I am struggling to identify it.
It was found buried in Lisbon by my aunt.  

I can't offer much details on it but here is what I have:

• Seems Greeks;
• Weight: 12 grams
• Diameter: 27 milimeter
• The inscription on the left seem: ΠΤΟΛΕΜΑΙΟΥ (Ptolemy in Greek)
  

Any help will be greatly appreciated.
Best regards.

please try here:
http://www.wildwinds.com/coins/

maybe a fake? no idea..

http://numismatics.org/collection/1967.152.651

This is fake of Ptolemaic Egypt, it's cast brass as you can see based on the surface of the coin.

Indeed, the white dirt can be found on many fake replica's

Citeer: KennyGThis is fake of Ptolemaic Egypt, it's cast brass as you can see based on the surface of the coin.

That grainy look on the surface had me suspicious too but I am by no means an expert in this matter. Thank you all for the help.