[Politically Correct]

But are you sure the “gold” you have in your hands is really gold ? Hasn’t there been counterfeit gold bars and coins discovered ? Made from tungsten with a heavy gold plating applied ? I’m not sure I’d believe it was really gold unless it was gold dust.

They used Tungsten to counterfeit large gold bars. Unless you own large bars it's unlikely that you have that problem.
As for the coins the ones being counterfeited are the rare coins not the common coins sold by the mint and most gold brokers. No one has ever found a tungsten coin, too tough to fabricate and too expensive.

[3niner]

As for the coins the ones being counterfeited are the rare coins not the common coins sold by the mint and most gold brokers.

This illustrates an important point. It is safer to invest in common coins which carry very little premium over the gold value. This eliminates most risk from counterfeiting, and rough handling.

[MSF BU]

Actually, there has been a problem with countfeit Panda’s (silver) being sold on Ebay. My policy is always to buy the common silver being sold over spot, mercury dimes and gold in tenths or quarter ounces. I have an open mind though and I’m always eager to read why I may be wrong in doing this.