Schröckingerite is a rare secondary uranium mineral often found as bright yellow, platy or rosette-like aggregates. It is highly prized by collectors for its brilliant yellow-green fluorescence under ultraviolet light. It typically occurs as an efflorescence in oxidized zones of uranium deposits.
Is this schröckingerite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch schröckingerite with a known reference. Schröckingerite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: subvitreous, pearly on {001}.
- 4Match the color rangeCompare against the expected color range: yellow.
- 5Look at form & habitCrystal system: triclinic. Typical habit: aggregates, globular.
Often confused with
Schröckingerite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads subvitreous, pearly on {001} on Schröckingerite and vitreous, pearly on {001} on Autunite.
How to tell apart: Streak differs, so Schröckingerite leaves pale yellow, Uranocircite leaves light yellow; luster reads subvitreous, pearly on {001} on Schröckingerite and pearly on Uranocircite.
Often found alongside schröckingerite
Minerals reported to co-occur with schröckingerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaCa₃(UO₂)(CO₃)₃(SO₄)F·10H₂O
- Mohs hardness
- 2.5
- Density
- 2.544-2.550 g/cm³
- Colors
- Streak
- Pale yellow
- Luster
- Subvitreous, pearly on {001}
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Aggregates, globular
- Cleavage
- Perfect on {001}
- Fluorescence
- Yellow green under SW and LW UV
- Rarity
- Uncommon
- Uses
- Collector, Scientific research
- Host rock
- An uncommon alteration product of uraninite in the oxidized zone of uranium deposits; may be of post-mine origin
Where rockhounds find schröckingerite
Classic worldwide localities
- Lost Creek, about 60 km north-northwest of Wamsutter, Sweetwater Co., Wyoming, USA
- Hillside mine, about 5.5 km north of Bagdad, Eureka district, Yavapai Co., and the Jack Daniels No. 1 and Foley Bros, Arizona, USA
- Grants district, McKinley Co., New Mexico, USA
- Troublesome Formation, Middle Park, Grand Co., and at a number of other places, Colorado, USA
- Evangelista vein, Jáchymov (Joachimsthal), and the Rozna uranium deposit, Czech Republic
- Radhausberg, near Bad Gastein, Austria
Field-hunting tip
Where it forms: An uncommon alteration product of uraninite in the oxidized zone of uranium deposits; may be of post-mine origin. If you start seeing gypsum, andersonite, bayleyite in float, you are in the right ground. Typical habit: aggregates, globular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify schröckingerite?+
Where is schröckingerite found?+
Is schröckingerite safe to handle?+
What rocks look like schröckingerite?+
What minerals are found with schröckingerite?+
What kind of rock does schröckingerite form in?+
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Find schröckingerite on the map
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