Clear Glass Lens

Taken all the way down to base materials, one Clear Glass Lens is 2 crafting steps deep and needs 1 intermediate — Natron ×1 — which resolves to 3 distinct raw materials totalling 3 units, plus 5 crystals.

That bill outweighs 3,373 of the 13,602 recipes tracked here and 426 of the 1,591 Alchemist ones, and 4,464 recipes nest deeper.

Only 3 of those crystals go into the final step; the other 2 are burned by the intermediates, so the real crystal cost is 5 Water Shard.

Every step is Alchemist work, from a Lv 25 intermediate up to the Lv 28 finish, so one class covers the whole chain.

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

Clear Glass Lens is itself consumed by 96 further recipes, spanning six of the eight crafting classes.