Stamp

Free colonies, far from "civilized space", have no legal tender. People who travel from one end of the system to the other will deal with both NMCs and Obols, but for the most part, they barter and trade and deal with mischmetal in the grey market. Mischmetal is a general term for an alloy of rare earth elements, the most common ones traded being Lanthanum, Europium, Erbium, Neodymium, Praseodymium, Gadolinium, and Dysprosium. Like all elements, each has their own value on the open market, which is tracked by a network of material brokers and traders. Due to its broad applications in electronics combined with its relative scarcity, Lanthanum naturally became the element used as the baseline for which the values of all other elements are measured. The metals used in electronic components are not designed to be used, disposed of, and reused like other materials, and so demand for them is the highest on frontier colonies that barter and trade in the Grey Market rather than use a standardized currency. There, mischmetals are compiled in both pure elemental bullion, and as round, solid metal alloy "coins" about half an inch thick called "stamps". One side is scored with lines forming a pie chart showing the elemental composition of the ingot, the other side displaying the percentile value of the coin relative to Lanthanum. Both of these stamps are etched into the metal when it is compiled, so there is no mechanical or metallurgical process involved, but the distinctive markings have nonetheless earned stamps their colloquial nickname.

Buyers and sellers store and carry their elements in bullion or ingot form before a transaction is made. In some markets, the transaction is handled electronically, and software using the most recently updated table of values analyzes the buyer's materials and calculates an alloy with the closest matching value down to the fourth decimal point. Then, a compiler deeks the appropriate elements and prints out a batch of stamps, which the seller later deeks and recompiles back into bullion form. Other markets play it more by ear, and both parties barter and trade with whatever ingots or bullion they have on hand. Stamps are the most common form of currency on the grey market in free outposts and frontier colonies, but in civilized space they are much less glamorously referred to as "blood metal". As part of the propaganda campaign against free colonization, government channels and corporations have painted free colonists, scrap divers, and free traders as a motley group of anarchists and gang members, and have spread the misconception that stamps are the currency of choice for criminals. Statistically this is true, but they are a rather small minority of the overall number of people who do use them, who are just trying to get by in the post-war solar system.