 The mineral occurs in a quartz-garnet-arsenopyrite matrix as white globules, tufted aggregates of fibrous crystals and radiating hemispheres of thin, colourless, bladed crystals.In his inaugural lecture as professor of chemistry at University College London, Nyholm spoke of his concern for the teaching of chemistry.In 1957 Nyholm organized the first of an annual series of Summer Schools at University College on new aspects of chemical knowledge and theory, and demonstrations of new equipment.