According to the FAQ for midas magic, there is a mining company that you can invest money in to get gold nuggets, where is it? And are there any other good ways to get gold?

Read the flyer in the shop regarding Broke Back Mining Co., it'll add a map marker for you. Gold, I assume you're still referring to gold nuggets and not money? If so, breakdown all the gold jewelry you find using the Aurum Assimulator, then combine the resulting gold fragments into nuggets.

thanks.