Yes, the state of Texas does accept gold as payment. I was not aware that other do. It is a point that is of little importance to the average person, but I could see where it might for others. It is not tracked by the banking system. I am curious how they determine the value of bullion gold. Certainly not by weight, without an assay.
There are now hand held electronic instruments that can be had for around $700 that can determine the carat value of gold.