Extremely rare. In polished section only, but questionable status at Tsumeb.
Paragenetic and General Notes
Bartelke (1976) cites Geier (1973/74) as recording that millerite could be detected in mixed ore by means of reflected light microscopy, a view reiterated by Pinch and Wilson (1977). However, Lombaard et al. (1986) consider the occurrence of millerite as questionable.