Darksteel Breastplate ★★

Taken all the way down to base materials, one Darksteel Breastplate is 3 crafting steps deep and needs 3 intermediates — Darksteel Rivets ×2, Darksteel Ingot ×1 and Darksteel Nugget ×4 — which resolve to 2 distinct raw materials totalling 21 units, plus 21 crystals.

That bill outweighs 8,152 of the 13,602 recipes tracked here and 780 of the 1,441 Armorer ones, and 337 recipes nest deeper.

Only 2 of those crystals go into the final step; the other 19 are burned by the intermediates, so the real crystal cost is 18 Fire Crystal, 1 Earth Cluster, 1 Fire Cluster and 1 other kind.

The chain crosses two disciplines — Armorer to Lv 50 and Blacksmith to Lv 50 — so no single class can finish it unaided.

1 of the 2 raw materials come out of the ground, and one of them is time-gated: Darksteel Ore (1:00). That window comes round once per Eorzean day, every 70 real-world minutes.

Darksteel Breastplate is itself consumed by 1 further recipe, all of them Armorer recipes.