Rare Earth Elements are gathered from Crater building sites in Lunar sectors by the Kreep Gatherers. Kreep stands for K (Potassium), REE (Rare Earth Elements) and P (Phosphorus). They are used in the production of Multispec Prisms in the Nano-Cutting Unit for Replicator production in Temperate sectors, and in the production of both Bioenhancers in the Cybernetics Factory and Anti-Grav Compensators in the Anti-G Workshop in Lunar sectors. Some Lunar sectors have a sector trait improving the production rate of Kreep Gatherers by 30%, but at the cost of a 50% increase in Maintenance Station credit maintenance. As an ingredient in 3 consumer products (Replicators, Bioenhancers, and Anti-Grav Compensators), its production is vital to maintain.
As the name suggests, Rare-Earth Metals have become infrequent during the last 200 years. While there are considerable deposits left deep in the Earth's crust, most companies refrain from opening them up - nobody wants the disaster in Ebashi Trench, where a geothermal plant caused tsanamis, to repeat itself. Good thing that, harvesting Rare Earths on the Moon is much less dangerous - if you ignore the lack of atmosphere and gravity. - Anno 2205 Website Description