- Supergene: post-mining oxidation & weathering deposits
- Bwlchrhennaid Mine, Goginan, Ceredigion: lathlike crystals to 0.3 mm (S.A. Rust Collection).
- Darren Mine, Pen-bont Rhydybeddau, Ceredigion: lathlike green crystals (S.A. Rust Collection).
- Dylife Mine, Penegoes, Powys: green laths associated with serpierite and wroewolfeite (S.A. Rust Collection).
- Eaglebrook (Nantycagl) Mine, Ceulanymaesmawr, Ceredigion: green laths (S.A. Rust Collection); additionally as scattered acicular to lathlike crystals and radial sprays to 1 mm, on corroded primary sulphide matrices (and often separated from the primary sulphide by a thin film of covellite). Associated minerals include brochantite and an uncharacterised mid-blue finely botryoidal phase (specimens in the National Museum of Wales Collection).
- Esgairhir Mine, Tal-y-bont, Ceredigion: noted by Cooper & Stanley (1990), redgillite was found here in the late 1980's by S.A. Rust and subsequently by other micromineral specialists. Associated with langite and covelline on corroded chalcopyrite, scattered redgillite laths can cover areas to several square centimetres. Sprays of crystals to 1 mm have also been noted.
- Frongoch Mine, Devil's Bridge, Ceredigion: redgillite occurs rarely as small groups of divergent green laths in association with langite, schulenbergite, caledonite, hemimorphite and hydrocerussite (listed as Unknown F2 by Green et al., 1996).
- Hendrefelin Mine, Ysbyty Ystwyth, Ceredigion: as tufts of acicular green crystals to 0.5 mm (S.A. Rust Collection) associated with an uncharacterised blue substance.
- Llechweddhelyg Mine, Penrhyncoch, Ceredigion: green laths (S.A. Rust Collection).
- Ponterwyd Mine, Llywernog, Ceredigion: green laths (S.A. Rust Collection).
- Cooper, M.P. & Stanley, C.J., 1990. Minerals of the English Lake District - Caldbeck Fells. Natural History Museum Publications, 160p.
- Green, D.I., Rust, S.A. & Mason, J.S., 1996. Classic British mineral localities: Frongoch Mine, Dyfed. UK Journal of Mines & Minerals, 17, 29-38.
- Pluth, J.J., Steele, I.M. & Kampf, A.R., 2005. Redgillite, a new mineral from Caldbeck Fells, Cumbria, England. European Journal of Mineralogy (submitted MS).