Argentum is the Refinement of Silver, and is practiced by Prometheans who study other supernatural creatures, such as spirits, vampires, werewolves, and mages, in hopes of gaining insight into humanity.
One path to Argentum comes from the idea that Prometheans stand out among supernaturals since they were never technically mortal. Even though most of them are made from human body parts, they have no memory of the life or lives those limbs and organs came from. However, vampires, werewolves, and mages almost always lead something of a normal mortal life before their transformations, and some Prometheans become fascinated by this. What does it say about humans that they can transform, or are transformed, into supernatural creatures? What does the nature of a particular transformation say about the human condition? Through understanding the supernatural, they seek greater understanding of humanity.
Not all followers of the Refinement of Silver have such deep reasoning or motivations; some Mystics come to Argentum out of an inability to fit in with humanity at all, and others simply because of an interest in the supernatural and occult. As a further extension, many Mystics also delve deeply into studies of madness and insanity, which often finds ways of often appearing among humans who claim to have had contact with supernatural creatures and are often dismissed or misdiagnosed.
Argentum is hard to discover by the nature of its subject matter; supernatural creatures are rare, even in the Chronicles of Darkness. Unless they are created with certain connections in mind, such as an existing throng or as an Ulgan, the average Promethean is unlikely to stumble upon another Promethean without pre-existing connections, let alone a vampire, werewolf, or other supernatural. In order to find Argentum, a potential Mystic must be very aware that Prometheans are far from alone in their unearthly existence. In addition, to properly benefit from the Refinement of Silver, they must see beyond themselves enough to realize that other supernaturals have their own forms of connections and relationships with mortals.
Naturally, the Ulgan, who are dominated by the humour of ectoplasm and spend so much time communicating with the beings of Twilight, are the ones who most often find the Refinement of Silver. Many Tammuz fear the unexplained and tend to shy away from Argentum, as do the Frankensteins, who often respond to the supernatural with anger and rage.