Phosphovanadylite-Ba
Chemical formula: BaV⁴⁺₄P₂O₁₀(OH)₆·12H₂O
Phosphovanadylite-Ba is a very rare secondary mineral, forming microscopic, platy crystals of an intense blue-green color.
Properties
- Mohs hardness
- 2
- Color
- Light green-blue
- Luster
- Vitreous
- Streak
- Very pale greenish blue
- Density
- 2.16
- Cleavage
- Perfect on {0001}
- Fracture
- Micaceous
- Transparency
- Transparent
- Crystal system
- Isometric
Diagnostic features
## Identification Identification of phosphovanadylite-Ba is based on its characteristic, vivid blue-green color, its occurrence as small, rosette-like aggregates of platy crystals, and its geological environment. Due to its microscopic size, field identification is practically impossible and requires laboratory analysis. ## Distinguishing from Similar Minerals This mineral can be confused with other secondary vanadium minerals of similar color, such as shcherbinaite, minasragrite, or other minerals from the phosphovanadylite group. Definitive differentiation is almost exclusively possible using advanced analytical methods, such as Raman spectroscopy or chemical analysis (EDS). ## Crystal Forms Crystals are very thin, platy, with a hexagonal outline. They usually form rosette-like or spherulitic aggregates, as well as thin coatings on rock surfaces.
Geological environment
## Genesis Phosphovanadylite-Ba is a secondary mineral, forming in the oxidation zones of uranium-vanadium deposits in sedimentary rocks (sandstones). It forms as a result of the weathering of primary vanadium minerals in the presence of barium and phosphorus. ## Mineral Associations This mineral co-occurs with other secondary uranium and vanadium minerals. At the type locality (Blue Streak mine, Utah), it was found in association with gypsum, shcherbinaite, minasragrite, pascoite, and quartz. ## Localities The only confirmed and described occurrence of phosphovanadylite-Ba in the world is its type locality: Blue Streak mine, Bull Canyon, Uravan District, San Juan County, Utah, USA.
Rarity
Extremely rare
For collectors
## Quality Criteria The quality of collector specimens depends on the richness and aesthetics of the crystal aggregates on the rock matrix. The most prized specimens are those with clearly formed, undamaged rosettes of intense blue-green color, contrasting with the substrate. Due to the microscopic nature of the mineral, the quality of the specimen when viewed under magnification is crucial. ## Popular Localities The only source of specimens is the Blue Streak mine in Utah, USA. Material from this locality is extremely rare and sought after by collectors specializing in rare minerals and "micromounts."
Care and storage
## Cleaning Specimens should be handled with the utmost care. Cleaning is not recommended due to the extreme brittleness and small size of the crystals. If absolutely necessary, compressed air can be used from a safe distance to remove loose dust particles. ## What to Avoid Avoid contact with water, chemicals, ultrasound, and all forms of mechanical cleaning (brushes, cloths). The crystals are very soft and brittle, susceptible to mechanical damage. Protect them from changes in temperature and humidity. ## Storage It is recommended to store specimens exclusively in specialized, sealed "micromount" boxes that protect against dust, shocks, and physical contact. Display should be in stable conditions, away from sources of vibration and direct sunlight.