Volume 1, Chapter 3 of the Mysterious Artifacts of Neo-Brutalist Dark Mores
Subsidiary Rarities are those objects that are so peculiar, they defy categorization. Like a velvet painting of a chicken in a top hat, or a taxidermy rabbit in a tutu.
Quantum Wool, for example, is a fabric woven from the very fabric of space-time itself. It's like a blanket, but also like the fabric of reality.
Or take the Chronalloy, a metal alloy that can only exist in the presence of a functioning clockwork.
Other notable Subsidiary Rarities include: