- The workers who perform these task are known as Belters.
Asteroids fall into three basic categories, each of which is different in nature and value:
- 1. Nickel-iron asteroids are reasonably dense, high-grade sources of metal of most value to the manufacturing industry. Moderately large asteroids can be sold to local shipbuilding concerns as planetoid starship hulls. Very large asteroids can be turned into space station hulls, the largest of them able to house millions (this is one of the steps of the colonization of planetoid belt worlds).
- 2. Carbonaceous asteroids are the most common planetoids and have the lowest value of all asteroids in most marketplaces. These stony chunks have the most value in systems where space colonies, large stations, and colonies on planets with no native biosphere can make use of several of the elements - carbon, hydrogen, oxygen, and so on - that can be extracted from them.
- 3. Ice chunks are made up of various frozen volatiles, including methane, water, and the like. These “dirty snowballs” are a source of hydrogen fuel and hence support an entire specialty of “ice miners” who seek them out. In systems where gas giants cannot be used for one reason or another, a starport or space station may pay reasonably good money for ice chunks, though mining ice for fuel will never make a belter rich. Mining ice for a desert world will pay more (until there is enough water in circulation to support the population, including any expected near-term growth), though substantial amounts of luck, foresight, and hard work are necessary to get significantly wealthy from this.
None of these three categories of asteroid is particularly valuable, and few belters ever made a major fortune strictly from discovering and mining any of these. (That said, many belters have made e comfortable living from discovering and/or mining large quantities of these, where there were few or no cheaper sources.) Major fortunes far more often come from the other things to be found:
- Many asteroids, most particularly nickel-iron rocks, contain varying amounts of the valuable minerals, platinum, iridium, and so forth, and sometimes other radioactive materials.
- Occasionally an asteroid will be discovered with an unusual configuration that makes it valuable for scientific or even aesthetic purposes.
- And, finally, there are artifacts, which take in the entire gamut from the flotsam of a week-old wreck to a trove left by the Ancients, and which vary in value accordingly.
Belt mining once referred to a strip mining method used on the surface of habitable worlds. Damage to the world's habitability aside, this tends to be more expensive than mining asteroid belts (or collections of asteroids at gas giant trojan points), in systems where such resources are to be found (most inhabited systems will have one or both). (Among other factors, the lack of gravity and ample working space means an asteroid can be blasted apart to get at the ore without worrying about tunnel collapse or shipping out the undesired rock bits.) For this reason, strip mining the surface of a world is no longer encountered as often as mining asteroids, so "belt mining" now most often refers to the latter.