I have been to the NY Federal Reserve Building and seen much of the gold - from the outside of the open door of the vault. This is the highlight of the public tour of the FRB in lower Manhattan. There are many different cages inside the vault - some containing just a handful of bars, and some with gold stacked near to the roof. But we are not told which cage corresponds to which country - that information is secret.

All the bars look identical, to me anyway - there are no stacks of coins or goblets etc. that I could see. (Not all the cages are visible from the vault entrance).

The Fed states in the tour that sovereign nations can keep their gold in the vault, virtually free of charge. And take it back at any time. This is basically a service to the world that the US has provided since the second world war, when much of Europe wanted - for obvious reasons - to move their gold to a safe haven.

As the Federal Reserve is a very secure place, and great value for money, I think most nations have been fine to use that - much cheaper and easier than building a facility that is equally secure.

So personally I'm not sure about the conspiracy theories saying that the Fed refuses to release the gold; to me that is easy for any nation to test - just ask for it, it could be done publicly except that you signal to any thief the date/time of when to attack :-)