Formula: NaCa3(UO2)(SO4)(CO3)3F.10H2.O
Compound carbonate
Crystal System: Triclinic
Specific gravity: 2.544 to 2.550 measured, 2.547 calculated
Hardness: 2½
Colour: Greenish yellow
Solubility: Soluble in water and in dilute acids
Luminescence: Bright yellow-green fluorescence under UV

Sedimentary environments

Schröckingerite is an uncommon alteration product of uraninite in the oxidised zone of uranium deposits; it may be of post-mine origin. Distinct crystals are rare; the common habit is crusts and globular aggregates of minute scaly grains. Associated minerals include gypsum, andersonite, bayleyite, swartzite, albrechtschraufite, liebigite, uraninite and dolomite (HOM, Lauf2).


At the type locality, the Svornost Mine, Jáchymov, Karlovy Vary District, Karlovy Vary Region, Czech Republic, schröckingerite occurs as an alteration product of uraninite (Dana). It occurs in a partly indurated arkose, as well as in gypsum (AM 33.152-157).

Schröckingerite from Svornost - Image

At the Hillside Mine, Bozarth Mesa, Bagdad, Eureka Mining District, Yavapai County, Arizona, USA, sulphides present in the vein include pyrite, arsenopyrite, galena, sphalerite, chalcopyrite, tetrahedrite and argentite; minerals of the oxidation zone include silver, chlorargyrite, cerussite, anglesite, smithsonite and hemimorphite. The country rock is mica schist, intruded by granite.
Uranium minerals were found in only one place, as a coating about 1/8 inch thick on gypsum, in the oxidised zone. The uranium carbonate minerals are clearly of secondary origin, and were deposited on the walls of the mine, but subsequent mining operations have completely obliterated the occurrence of these secondary minerals.
Adhering to the micaceous schist are scattered green rosettes of schröckingerite, with sulphur-yellow bayleyite. Overlying this schist is a layer of snow-white granular gypsum containing small clusters of vivid green swartzite. Coating gypsum is a mass of yellow bayleyite, most of it now altered to a pale-yellow powder. The rare andersonite is easily overlooked (AM 36.1-22).

At the Section 22 deposit, Ambrosia Lake subdistrict, McKinley county, New Mexico, USA, the presence of schröckingerite has been noted as an encrustation on sandstone from a mine wall. In the sample, the predominant mineral was gypsum with lesser amounts of andersonite and schröckingerite. Certain other samples from the mine walls were found to consist only of gypsum and andersonite (AM 51.929-930).

Schröckingerite from Ambrosia Lake - Image

At the Kinkel Quarry, Bedford, Westchester county, New York, USA, schröckingerite occurs in a pegmatite (AM 20.62-63).

At the Shinarump No 3 Mine, Seven Mile Mining District, Grand county, Utah, USA, schröckingerite occurs associated with gypsum in seams in shale (AM 39.901-907). Abundant gypsum is also present (AM 44.1020-1025).

Near Wamsutter, Sweetwater county, Wyoming, USA, small concretions of schröckingerite are disseminated in considerable abundance in gypsum. The gypsum occurs mostly as small crystals with a little sand and the schröckingerite. It is a surface deposit in a semi-arid region. The country rocks in that part of Wyoming are sedimentary (AM 22.561-563 as dakeite).

Schröckingerite from Wamsutter - Image

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