Holy Rainbow Hat of Healing

Taken all the way down to base materials, one Holy Rainbow Hat of Healing is 4 crafting steps deep and needs 6 intermediates — Holy Rainbow Cloth ×3, Mythrite Nugget ×1, Holy Water ×6 and 3 others — which resolve to 7 distinct raw materials totalling 38 units, plus 37 crystals.

That bill outweighs 11,698 of the 13,602 recipes tracked here and 1,682 of the 1,968 Weaver ones, and 1 recipe nests deeper.

Only 7 of those crystals go into the final step; the other 30 are burned by the intermediates, so the real crystal cost is 23 Lightning Crystal, 6 Water Crystal, 3 Fire Crystal and 2 other kinds.

The chain crosses three disciplines — Weaver to Lv 54, Alchemist to Lv 52 and Blacksmith to Lv 51 — so no single class can finish it unaided.

6 of the 7 raw materials come out of the ground, and one of them is time-gated: Dravanian Mistletoe (0:00, 12:00). The widest gap between consecutive opening times is 12 Eorzean hours, about 35 real-world minutes.

Of the intermediates, Rainbow Thread has the widest use: 116 recipes call for it, spanning five of the eight crafting classes.