Mineralpedia Details for Derriksite
Named for Jean Marie Francois Joseph Derriks, a Belgian mineralogist who studied the uranium deposit at Shinkolobwe in the Democratic Republic of the Congo. This is the same country where Derriksite finds its type and only locality at the Musonoi mine at Kolwezi in the Katanga Copper Crescent. It occurs there in the oxidized selenium-bearing copper-cobalt deposit. Associated minerals include selenian digenite, chalcomenite, demesmaekerite, and malachite. Derriksite is quite radioactive.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/derriksite.pdf
Derriksite from Musonoi mine, Kolwezi, Shaba Cu belt, DR of Congo
The Derriksite, at the red arrows, is glassy, dark green, somewhat prismatic crystals around 1mm and in clusters to from 2-4mm.