Jordan, this is a great question. Thanks for coming to the CfPA Ecosystem for insights.
Of course, there is no industry or sector that can be thought of as traditionally raising money via crowdfunding. The industry is too new, implemented just six years ago and really gaining scale only in the past two years. We're all learning.
There is no reason you can't crowdfund for a gold mining operation. Obviously, this is a great time to be investing in gold.
FINRA-registered portals are required to do some screening to prevent fraudsters from attempting to raise money on their platforms. Portals are allowed to do some additional screening to curate a theme. They are not allowed to imply that they have done thorough underwriting of an offering. Broker-Dealers, like Start Engine, that operate portals are allowed to do more and charge more than the other portals, including offering more help raising money.
Some platforms focus on serving small business, real estate, tech or other niches. While I haven't spotted a portal focused on extractive industries, one may exist. However, you can test out the large players (Wefunder, Republic and StartEngine) where you are most likely to find admission.
You want to remember that there is no magic crowd; the money you raise will come from your networks primarily.
Good luck!