So this stuck in my head and I’m just wondering if there was a defined answer out there, I read at one point that the metals were less a conduit of investiture but more a chemical key for a scadrian to access their connection to preservation based of their genetic spirit web. But in secret history it’s noted that metal on the planet glows, but when Kelsier finds and filches metal from Kriss and Nazh it doesn’t glow at all, implying there some kind of power in metal of scadrial not just a chemical key. Which leaves me wondering what the actual answer is here, if allomantic metals are only Available on scdrial eventually they are going to run out, what would that mean for era 3 and 4?

Edit damn this blew up, I got it guys thanks