Honestly, there is little reason to not be able to smuggle tons of gold. If you have access to gold in those quantities than you can presumably access aqua regia. In which case hundreds of pounds can be turn into very difficult to trace liquid gold salts.

@ultimape check it out cinnamon can be used in place of urea and sodium metabisulfite for gold precipitation. https://www.popsci.com/science/article/2010-11/cinnamon-could-replace-harsh-chemicals-produce-gold-nanoparticles-researchers-say/

Maybe not very difficult but a normie would think its urine. If you kept a cotton ball wetted with uric acid on the lid then you could further distract. Chances of someone presuming in solution gold is valuable is insanely slim largely based on the handler of the liquid.

Studying gold and any of it facets enthrall me. None more than there sheer domination of gold information that exists in cyberspace. Study gold and noble metals indepth of long periods and you start to see.... Things