Stell
From Jenny Everywhere Wiki
Stells were a very expensive physical currency sometimes used in interdimensional dealing. Though resembling a “dull white coin”, a stell contained “the full materials of a star, compressed to a few centimetres”. The Cult of Acantha paid Lainya Vantrik five stells to assassinate Briar, or more specifically the version of her who did not become Acantha. Vantrik eventually refused to fulfill the contract when she learned how young Briar was, but opted to keep the payment for her trouble. (PROSE: Century Smith and the Time Terror)