Rhodonite

Nothing in this list is craftable in turn, so one Rhodonite is a single step: 4 units of material drawn from 2 base items, plus 6 crystals.

That bill outweighs 3,935 of the 13,602 recipes tracked here and 504 of the 2,216 Goldsmith ones, and 9,374 recipes nest deeper.

Both raw materials are gathered, and one of them is time-gated: Raw Rhodonite (8:00, 20:00). The widest gap between consecutive opening times is 12 Eorzean hours, about 35 real-world minutes.

Rhodonite is itself consumed by 56 further recipes, spanning seven of the eight crafting classes.