Ni and Co content of chondritic metal

Abstract

WE have made a detailed study of the metal phases in some chondrites. Axon and Goldstein have reported¹ micro-probe measurements of the Ni and Co contents at the interfaces between contiguous α and γ phases in seven metallic particles of high Co content from Apollo 14 and 15 lunar soils. The three particles of highest Co content had α phase in contact with clear homogeneous γ phases (Fig. 1), whereas the particles of lower Co content (Fig. 1) had Widmanstãtten spindles of α phase in a matrix of high Ni γ phase in a manner analogous to that observed in certain Ni-rich ataxite irons. Axon and Goldstein have expressed the view that the Co contents of these particles are “higher than the meteorites of similar structure” and that they must have come from a different source.