Gathering brings in the raw goods. Refining makes the common materials from them, and refining a common one again with an additive makes the uncommon ones. Production takes them from there.
Common metal, refined from Silver Ore by Smelting at level 1 (recipe).
One Silver Ingot takes 4 Silver Ore and 1 Chunk of Coal.
Production takes it, or its forms, in 4 Blacksmithing, 3 Alchemy, 1 Carpentry, and 1 Tailoring recipes.