Bluelizardite
Chemical formula: Na<sub>7</sub>(U<sup>6+</sup>O<sub>2</sub>)(S<sup>6+</sup>O<sub>4</sub>)<sub>4</sub>Cl·2H<sub>2</sub>O
Bluelizardite is a very rare, water-soluble uranyl sulfate, forming characteristic, blue, acicular crystals.
Properties
- Mohs hardness
- 2
- Luster
- Vitreous
- Streak
- Light blue
- Density
- 2.83
- Cleavage
- Perfect on {010}
- Fracture
- Splintery
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
Diagnostic features
## Identification Key diagnostic features of bluelizardite are its intensely blue color, acicular or fibrous crystal habit, and water solubility. Strong radioactivity is also a characteristic feature. ## Distinguishing from Similar Minerals It can be confused with other blue, secondary uranium minerals, such as chalcanthite or some varieties of uwanoite. However, immediate water solubility is a unique feature of bluelizardite that allows it to be easily distinguished. Chalcanthite is also soluble but is not radioactive. ## Crystal Forms Bluelizardite forms aggregates of very fine, acicular crystals, often arranged in radial or tangled aggregates. Individual crystals are rarely visible to the naked eye.
Geological environment
## Genesis It is a secondary mineral, formed in the oxidation zones of uranium deposits. It crystallizes in a dry environment, as a result of the evaporation of waters rich in uranium, sulfates, and chlorides. Its formation is associated with the weathering processes of primary minerals, such as uraninite, in the presence of pyrite (a source of sulfates). ## Mineral Associations Bluelizardite occurs in association with other secondary uranium minerals, such as natrozippeite, gypsum, chalcanthite, uwanoite, and also with clay minerals of the Chinle Formation. ## Localities The only confirmed occurrence of this mineral worldwide is its type locality – the Blue Lizard Mine, located in White Canyon, San Juan County, Utah, USA.
Rarity
Extremely rare
For collectors
## Quality Criteria The most valued specimens are those that exhibit an intense, pure blue color and form rich, dense aggregates of acicular crystals on the matrix rock. Due to the mineral's instability, it is crucial that the specimen is well-preserved and properly protected. The size and aesthetics of the matrix also influence its value. ## Popular Localities The only source of bluelizardite specimens is the Blue Lizard Mine in Utah, USA. All samples available on the collector's market originate from this single locality.
Care and storage
## Cleaning The mineral must under no circumstances be cleaned wet, as it immediately dissolves in water. Mechanical cleaning is also inadvisable due to the extreme brittleness of the crystals. Specimens should be left in the state in which they were found. ## What to Avoid Contact with water and humid air, which lead to rapid degradation of the mineral, should be avoided. Protection against temperature and humidity changes is essential. Due to radioactivity, exposure should be limited, and it should be stored away from areas of permanent human presence, using appropriate safety precautions. ## Storage Bluelizardite specimens require storage in hermetically sealed containers, preferably with the addition of a desiccant (e.g., silica gel). Display should only take place in sealed, transparent display cases, away from direct sunlight and heat sources.