Initiate's Alembic

Taken all the way down to base materials, one Initiate's Alembic is 3 crafting steps deep and needs 4 intermediates — Bronze Rivets ×1, Iron Plate ×1, Iron Ingot ×2 and 1 other — which resolve to 3 distinct raw materials totalling 9 units, plus 7 crystals.

That bill outweighs 5,492 of the 13,602 recipes tracked here and 519 of the 1,441 Armorer ones, and 337 recipes nest deeper.

Only 2 of those crystals go into the final step; the other 5 are burned by the intermediates, so the real crystal cost is 4 Fire Shard, 2 Ice Shard and 1 Earth Shard.

The chain crosses two disciplines — Armorer to Lv 18 and Blacksmith to Lv 16 — so no single class can finish it unaided.

All 3 raw materials are gathered, and not one of their spots is timed, so nothing in the tree waits on the Eorzean clock.

Of the intermediates, Iron Ingot has the widest use: 113 recipes call for it, spanning seven of the eight crafting classes.