Murdochite is a mineral combining lead and copper oxides with the chemical formula (x ≤ 0.5).
It was first discovered in 1953 in the Mammoth-Saint Anthony Mine in Pinal County, Arizona by Percy W. Porter, a mining engineer who handpicked a 401.5-mg sample. Porter would later submit for analysis and it was then that Fred A. Hildebrand suggested that the sample was a new mineral after taking a powder x-ray picture. Murdochite was first suggested to be of a cubic structure. After this suggestion, the term "murdochite-type structure" began to be used when describing a structure that is similar to that of murdochite. Murdochite was later found to be octahedral.
Composition
Various studies have examined the composition of murdochite. When murdochite was first discovered, its chemical formula was determined through stoichiometry to be Cu<sub>6</sub>·1Pb0·9O<sub>8</sub>·O. This new composition was also proven incorrect and the formula that is widely accepted today, (x ≤ 0.5), was proposed. Samples from T. Khuni mine indicate that polished sections of murdochite resemble the color and reflectivity of magnetite but vary because of zoning. The lighter zones in murdochite are caused because they are richer in lead than the darker zones.
Origin of the name
The mineral murdochite is named after Joseph Murdoch, who was once a professor of geology at the University of California, Los Angeles and a past president of the Mineralogical Society of America. Professor Murdoch was born February 19, 1890, and died December 31, 1973, at 83 years of age.