Carborix

Description
A tiny rock planet with a thin, reducing atmosphere, Carborix has been remotely mined for millennia, first for rarer platinum-group metals and radioactives, then catalysts and semi-conductors, and eventually structural materials like titanium, iron, and nickel. The recovery operations were grinding to a halt just before the Reapers hit the planet, turning the orbital stations and the turians' early-warning satellites into molten metal.