[TheOldLady]

Good grief! You'd think that they would weigh every bar of gold they receive. Density doesn't lie. If it isn't 19.32 g/cm³, it isn't gold.

[phockthis]

try doing some research.....

[AFreeBird]

Gold (Au) Density [kg/m³: 19300
Gold (Au) Tungsten (W) Density [kg/m³: 19250

Very very close.

And from another site...

A Chinese company called Chinatungsten is advertising imitation gold merchandise on its website. The following quote is taken directly from their Tungsten Alloy for Gold Substitution page:

"a coin with a tungsten center and gold all around it could not be detected as counterfeit by density measurement alone ... We are well accustomed to exploit more innovative applications of tungsten products. Gold-plated tungsten is one of our main products."