Currency in Zitis takes the form of the Silver Mark, a ring-shaped unit of silver (sometimes adultered with lead). The Mark takes its from from the old rings of Zlathet (City), a Riverine city. These original marks were meant to be worn to make them easy to carry. Over time, the ring hole has become significantly smaller, and the ring itself flatter, such that multiple rings may be carried easily on a string - this allows easy handling of larger currency amounts. The Mark is a standard form across Zitis, but it is not minted in any standardized fashion, and the value of a Mark is based on the weight of the silver contained. Most states have somewhat standardized values of what coin can be appraised to hold the value of a Mark, and these are used in audited transactions and in fees and taxes.