how do I determine if an ancient coin is real or counterfeit from a photo?

Are ancient counterfeit coins valuable? (counterfeited during ancient time) I want to buy a roman coin but it might be have been counterfeited during ancient times…is it worth buying? It is worthless?...
Of 12 coins in a bag 1 is counterfeit and weighs less what is the least weighings to determine the counterfeit? please explain your answer...
if a greek coin is dated 460 B.C., how will anyone know if it is real or counterfeit? ...
How can you use a simple balance three times to determine which coin is counterfeit? You have twelve coins, one of which is a counterfeit and weighs less than the legal coins. How can you use a simple balance three times to determine which coin...
You have 30 gold coins but one is counterfeit and lighter than a real coin. The only equipment you have is…? Use lateral thinking. You have 30 gold coins but one is counterfeit and lighter than a real coin. The only equipment you have is a simple pair of balance scales....