Formula: (NH4)2Mn[(UO2)4O4(SO4)2](H2O)4
Sulphate, uranyl mineral
Crystal System: Monoclinic
Specific gravity: 4.633 calculated for the empirical formula, 4.688 calculated for the ideal formula
Hardness: 2
Streak: Pale orange
Colour: Red-orange
Luminescence: Not fluorescent under long wave or short wave UV
Solubility: Easily soluble in room-temperature dilute hydrochloric acid

Sedimentary environments
Hydrothermal environments

Redcanyonite is a relatively new mineral, approved in 2016 and to date (September 2023) reported only from the Red Canyon mining district.


At th type locality, the Blue Lizard Mine, Red Canyon Mining District, San Juan County, Utah, USA, redcanyonite occurs underground. Secondary uranium mineralisation in Red Canyon is often localised and most prevalent within organic-rich beds that are laced with uraninite and sulphides. The source of NH4+ is inferred to be from decomposition of organic material. Redcanyonite occurs intimately associated with ammoniozippeite in several specimens. Other associated secondary minerals include bobcookite, brochantite, devilline, gypsum, johannite, posnjakite, natrozippeite, pentahydrite and pickeringite.
Redcanyonite occurs as radial aggregates, up to 1 mm in diameter, of needles and blades individually measuring up to 0.2 mm long. Many crystals are twinned. The crystals are translucent with a vitreous lustre and pale orange streak (MM 82.6.1261-1275).

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