Oh, it's just copper, iron, gold and 2 exotic ores in purple and turquoise.
Viewing post in World of Solaria: Crafting Materials Icon Pack comments
I've literally got them listed as Exotic Ore 1 and 2 on the guide image. I like to leave some things up to devs for their worldbuilding. The icons are easily recoloured too, to better fit their vision. Here's a list of fantasy metals and their properties https://www.gmbinder.com/share/-MiKX6oEHFc5UOZkYatR