Thin fracture coatings and vug linings of botryoidal, dark green to black dufrenite have been observed very rarely, associated with radial sprays of strengite, minute cubic crystals of pharmacosiderite, and local sprays of meurigite.
2 mm of radiating, pale yellow meurigite crystals associated with strengite have been discovered on selected dufrenite specimens.
Hirson (1965) reported the presence of dufrenite
in association with heterosite as an alteration product of triphylite but gave no further description.
In various other Indian Mountain prospects there occur kidwellite pseudomorphs after small dufrenite
crystals, and fine medium-purple strengite balls to 5 mm on dark matrix, resembling those from Svappavaara, Sweden.