We have conducted experiments on 16 lunar soils and 3 lunar volcanic glass samples to study the extraction of oxygen, an important resource for future lunar bases. The samples were chosen to span the range of composition and mineralogy represented in the Apollo collection. Each sample was reduced in flowing hydrogen for 3 hours at 1050°C. The dominant effect was reduction of Fe2+ (as FeO) in minerals and glass to iron metal, with concomitant release of oxygen. Oxygen extraction was strongly correlated with initial Fe2+ abundance but varied among mineral and glass phases. The experimental reduction of lunar soil and glass provides a method for assessing the oxygen production potential for sites on the lunar surface from lunar orbit. Our results show that oxygen yield from lunar soils can be predicted from knowledge of only one parameter, total iron content. This parameter can be measured from orbit by gamma ray spectrometry or multispectral imaging. Such data can provide a quantitative estimate of oxygen production potential anywhere on the Moon.