Meyrowitzite is an extremely rare secondary uranium mineral typically occurring as delicate acicular to fibrous yellow crystals. It is primarily found as a localized mineral crust within uranium-bearing sandstone deposits and is prized by serious collectors of uranyl minerals.
Is this meyrowitzite?
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 meyrowitzite with a known reference. Meyrowitzite sits at Mohs ~2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: very pale yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular or fibrous crystal aggregates.
Often confused with
Meyrowitzite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside meyrowitzite
Minerals reported to co-occur with meyrowitzite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca(UO₂)(CO₃)₂·5H₂O
- Mohs hardness
- ~2
- Density
- 2.70 g/cm³
- Colors
- Streak
- Very pale yellow
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular or fibrous crystal aggregates
- Cleavage
- Perfect on {1̄01}
- Fluorescence
- Fluoresces weak greenish yellow to moderate greenish blue under 405 nm laser
- Rarity
- Rare
- Uses
- Collector
- Host rock
- On calcite-veined asphaltum as efflorescent crusts on the surfaces of mine walls in a sand-hosted uranium deposit of the Colorado Plateau type
Where rockhounds find meyrowitzite
Classic worldwide localities
- Markey mine, Red Canyon, White Canyon District, San Juan County, Utah, USA
Field-hunting tip
Where it forms: On calcite-veined asphaltum as efflorescent crusts on the surfaces of mine walls in a sand-hosted uranium deposit of the Colorado Plateau type. If you start seeing gypsum, markeyite, rozenite in float, you are in the right ground. Typical habit: acicular or fibrous crystal aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify meyrowitzite?+
Where is meyrowitzite found?+
Is meyrowitzite safe to handle?+
What rocks look like meyrowitzite?+
What minerals are found with meyrowitzite?+
What kind of rock does meyrowitzite form in?+
What is meyrowitzite used for?+
Find meyrowitzite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
