Purification Module ★★★

Taken all the way down to base materials, one Purification Module is 3 crafting steps deep and needs 4 intermediates — Darksteel Plate ×4, Cobalt Plate ×3, Darksteel Nugget ×8 and 1 other — which resolve to 4 distinct raw materials totalling 43 units, plus 84 crystals.

That bill outweighs 12,178 of the 13,602 recipes tracked here and 1,293 of the 1,441 Armorer ones, and 337 recipes nest deeper.

Only 3 of those crystals go into the final step; the other 81 are burned by the intermediates, so the real crystal cost is 30 Fire Shard, 24 Fire Crystal, 15 Ice Shard and 3 other kinds.

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

3 of the 4 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.

Of the intermediates, Cobalt Ingot has the widest use: 145 recipes call for it, spanning seven of the eight crafting classes.