Mythril Alembic

Taken all the way down to base materials, one Mythril Alembic is 3 crafting steps deep and needs 5 intermediates — Eye of Earth ×1, Mythril Plate ×1, Mythril Rivets ×1 and 2 others — which resolve to 4 distinct raw materials totalling 13 units, plus 34 crystals.

That bill outweighs 6,426 of the 13,602 recipes tracked here and 599 of the 1,441 Armorer ones, and 337 recipes nest deeper.

Only 9 of those crystals go into the final step; the other 25 are burned by the intermediates, so the real crystal cost is 19 Fire Shard, 9 Ice Shard, 4 Earth Shard and 1 other kind.

The chain crosses three disciplines — Armorer to Lv 40, Blacksmith to Lv 39 and Goldsmith to Lv 23 — so no single class can finish it unaided.

All 4 raw materials are gathered, and not one of their spots is timed, so nothing in the tree waits on the Eorzean clock.

Mythril Alembic is itself consumed by 1 further recipe, all of them Armorer recipes.