Dark Chestnut Rod

Taken all the way down to base materials, one Dark Chestnut Rod is 3 crafting steps deep and needs 3 intermediates — Growth Formula Epsilon ×3, Dark Chestnut Lumber ×1 and Quicksilver ×3 — which resolve to 5 distinct raw materials totalling 27 units, plus 23 crystals.

That bill outweighs 9,763 of the 13,602 recipes tracked here and 1,005 of the 1,552 Carpenter ones, and 337 recipes nest deeper.

Only 7 of those crystals go into the final step; the other 16 are burned by the intermediates, so the real crystal cost is 9 Water Crystal, 8 Wind Crystal, 3 Ice Crystal and 1 other kind.

The chain crosses two disciplines — Carpenter to Lv 54 and Alchemist to Lv 51 — so no single class can finish it unaided.

4 of the 5 raw materials come out of the ground, and one of them is time-gated: Volcanic Rock Salt (17:00). That window comes round once per Eorzean day, every 70 real-world minutes.

Of the intermediates, Dark Chestnut Lumber has the widest use: 74 recipes call for it, spanning six of the eight crafting classes.