It does not make sense for any advanced alien civilisation to be interested in any terrestrial resource.
You have gravity, possibly hostile atmosphere and temperature, flora, fauna, microbes and viruses, and a recalcitrant, violent, unreliable dominant species as obstacles, and most of the minerals are buried deep inside the planet.
Why would they go to the effort of coaxing the apes into harvesting gold for them, when
1. The apes will only ever scratch the literal surface of the planet, having access to less than a fraction of the gold available.
2. It takes them thousands of years to do so.
3. There being a good chance the apes will wipe themselves out before even that.
They would be far better off to simply harvest any resources they want from asteroids with autonomous robots.
Zero G, no atmosphere, no plants or animals in the way, no need for cracking open a planet to get to most of the resources.
Even just blowing up the planet and then harvesting the resulting asteroid belt would be a better solution.
Even if they were interested in biological resources of Earth, like human meat, it would make far more sense for them to just pick some samples, and use them to cultivate them in mass farming facilities inside O’Neill cylinders, where they could not only ensure that they are obedient at all times through genetic modification, but also control their eating habits, so that they do not spoil the meat harvest through unhealthy dieting.