Definitive X-ray powder data for covellite, anilite, djurleite, and chalcocite

By using the Guinier-Hägg focusing X-ray powder camera with CrKα₁ and CuKα₁ radiations, new powder data for covellite (CuS), anilite (Cu₇S₄, djurleite (Cu_1.934S), and low chalcocite (Cu₂S) have been obtained from synthetic and natural materials. The powder data were treated by least-squares analysis to obtain the best unit-cell parameters consistent with the data. These powder data are intended to replace inferior and incomplete data previously published and to serve as standards for the study of copper sulflde minerals.