Ampoule of starlight

Looking like a strangely glowing pharmaceutical prised from the depths of the Wellspring, possession of an ampoule of starlight not only reduces the the cooldown on switching between the alchemical fields (Sublimation and Formulation) to one Achaean day but also completely removes the lesson cost for doing so. It is sold at the Class Artefacts Shop: Alchemist - Jester in Delos.