Zippeite on Uraninite From the Blue Lizard Mine

Jan 5

4 min read

A Detailed Look at Secondary Uranium Alteration in the San Juan Basin

Zippeite on Uraninite

Zn(UO₂)₂(SO₄)₂(OH)₂·4H₂O on UO₂

Blue Lizard Mine

San Juan County

Some uranium specimens impress through brute force. Others explain chemistry in motion. This zippeite on uraninite from the Blue Lizard Mine belongs firmly in the second category.

This piece is not about raw output alone. It is about transformation. It captures a late-stage, significant moment in uranium alteration where primary UO₂ has begun to weather, hydrate, oxidize, and reorganize into fragile, expressive secondary minerals. Zippeite does not hide the process. It puts it on full display.

The Name: Where Zippeite Comes From

Macro detail of zippeite crystals forming on uraninite matrix Blue Lizard Mine

The mineral zippeite was named in 1850 in honor of Franz Xaver Zippe, an Austrian mineralogist and curator who made significant contributions to early mineral classification and museum collections in Europe.

Zippeite belongs to a family of hydrated uranyl sulfates. These minerals form only under particular conditions. Uranium must already be oxidized. Sulfate must be present. Water must move slowly enough to allow crystal growth rather than complete dissolution. The result is a mineral that is chemically delicate and geologically precise.

Zippeite does not form deep underground. It forms at the surface or near the surface where oxygen, water, and time intersect.

The Locality: Blue Lizard Mine, Utah

The Blue Lizard Mine is located in the uranium-rich uranium-bearing sandstone deposits of southeastern Utah within the broader Colorado Plateau uranium province. This region supplied significant uranium ore during the Cold War era and remains one of the most studied uranium-bearing sulfate-rich landscapes in North America.

Unlike massive hard rock uranium deposits, the Blue Lizard Mine produced uranium hosted in porous sandstone. This matters. Sandstone allows fluids to move. Fluids move uranium—and sulfate-rich fluids where uranium moves, secondary minerals form.

Zippeite from this locality represents oxidation and sulfate rich conditions that developed after primary mining activity exposed uraninite to air and water. This is post-ore mineralogy in the most literal sense.

What This Specimen Actually Shows

This specimen consists of uraninite(UO₂), the primary uranium source, with zippeite forming a secondary crust and vein filling along fractures and exposed surfaces.

The yellow-to-yellow-green material is zippeite. The darker, dense core is uraninite. The boundary between them is where the science happens.

This is not a replacement pseudomorph. It is an active alteration interface. Uranium is migrating outward. Sulfates are binding it. Hydration stabilizes it just long enough for crystals to exist.

That is why zippeite is rare in stable collections. It forms late, and it does not last forever.

Ultraviolet Fluorescence Behavior

Bright green fluorescence of zippeite on uraninite under shortwave UV light

Under shortwave ultraviolet light, the zippeite fluoresces a bright, electric green. This fluorescence arises from the uranyl ion, UO₂²⁺, which strongly responds to UV excitation.

The glow is not uniform. It traces specific zones where uranium concentration and oxidation state favor uranyl formation. This makes fluorescence not just a visual effect but a chemical map.

Areas with the strongest fluorescence are often the most fragile. They represent peak alteration rather than stability.

Radiation Output and Spectral Character

Radiacode detector measuring zippeite on uraninite Blue Lizard Mine Utah

When measured with consistent geometry and acquisition time, this specimen produces a strong response relative to its size. Counts are elevated but not dominated by dense primary ore behavior.

Gamma spectrum of zippeite on uraninite showing uranium decay chain

The spectrum shows clear uranium-series features with radium daughters present, consistent with altered uraninite rather than thorium-dominated material. This aligns with expectations for Colorado Plateau uranium minerals.

Notably, the spectrum supports what the specimen visually communicates. Uranium is present, active, and decaying in place, but it has moved from a compact crystalline lattice into hydrated surface phases.

This is uranium after exposure.

Why Secondary Uranium Minerals Matter

Collectors often chase primary minerals. Dense uraninite. Sharp crystals. High numbers. Secondary minerals tell a different story.

Zippeite records uranium mobility. It shows how uranium behaves once oxygen and water are introduced into the system through mining, erosion, or natural exposure. This has implications far beyond collecting.

Understanding these minerals helps explain uranium transport in groundwater, challenges in mine remediation, and the environmental behavior of radioactive elements.

This specimen is not just collectible. It is educational.

How This Fits Into My Hot Box

In my Hot Box display, this specimen sits near other late-stage alteration minerals rather than primary ores. It represents chemistry over mass.

Where solid uraninite commands attention through sheer output, zippeite earns it through expression. It glows. It weathers. It reacts. It reminds viewers that uranium continues to evolve once it leaves the ground.

This is a specimen that invites conversation, not caution tape.

Why Blue Lizard Zippeite Is Special

Blue Lizard Mine zippeite combines three things rarely found together in one piece:

• A clear uraninite source

• Well-developed secondary mineralization

• Strong, clean uranyl fluorescence

Many zippeite specimens exist as crusts or powders. Fewer occur in a readable association with their parent mineral. This makes Blue Lizard material especially valuable for study and documentation.

Up Next

Skłodowskite From Musonoi Mine

If zippeite represents uranium at a late, sulfate-driven stage of alteration, skłodowskite shows what happens when uranium continues moving and encounters silica-rich fluids under oxidizing conditions. The following article shifts from sulfate-bound surface alteration to hydrated uranium silicates, where uranium mobility is preserved in granular, crusty aggregates rather than fragile sulfate crystals. Skłodowskite from the Musonoi Mine captures uranium mid-journey, not yet locked into stability but no longer bound to its primary source. It is a transition mineral in the truest sense, and a key step in understanding how uranium chemistry evolves once exposure begins.