Were you on your last dime, your family destitute, the ideals you hold so true might be compromised. Were you wealthy enough that this was but a token, returning it would be easier.
I think we have a lot of idealists on this forum, but I wonder if they could walk the talk. Those who have said they would take the gold are being honest. I appreciate that. Those who repeat the moral obligation to return the gold may be correct about their values, but do they live them? Surrounded by wealth and no repercussions for taking it, many an honest man will turn.
I have been in this position a few times. I can honestly say that it would depend on the circumstance. Once, I was barely able to feed my children and keep a roof over our heads. Times were very tough and I found $1400. At the time, $1400 was more than a month's wages. I saw it as a blessing and spent it wisely. Countless other times, I had enough to get by. Not excess, but enough. In every one of those times, I searched extensively for the individual that lost the item and returned it. I once drove clear across the city to return a wallet to a lady and no I did not accept her finder's fee.
I aspire to be noble, but will admit that circumstance does influence my actions. In the absence of misery, I am honest and true. I am not the same individual when destitute. I suspect that those with strong ideals would find themselves making similar compromises if life dealt them some really rough blows.
Barring the worst of personal circumstance, I would return the gold. But I have answered no because in the depths of despair, that conviction could be challenged.