Adolfpateraite
Chemical formula: K(U<sup>6+</sup>O<sub>2</sub>)(S<sup>6+</sup>O<sub>4</sub>)(OH)(H<sub>2</sub>O)
Adolfpateraite is a rare, radioactive secondary uranium mineral, forming characteristic, acicular crystals of an intensely yellow color.
Properties
- Mohs hardness
- 2
- Luster
- Vitreous
- Streak
- Light yellow
- Density
- 3.75
- Cleavage
- Good on {010}
- Fracture
- Uneven
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
Diagnostic features
## Identification Key diagnostic features of adolfpateraite include its bright yellow color, crystal habit (thin prisms, needles) forming radial aggregates, and strong radioactivity. It occurs as a product of post-magmatic processes on the walls of old mine workings. ## Distinguishing from Similar Minerals Adolfpateraite can be confused with other yellow secondary uranium minerals, such as uranopilite, zippeite, or johannite. Uranopilite often forms spherical aggregates, and zippeite forms crusts composed of microscopic lamellae. Certain differentiation of these minerals usually requires advanced analytical methods, such as X-ray diffraction (XRD). ## Crystal Forms Crystals are prismatic, elongated along one axis, often acicular. They typically occur in radial or fan-shaped aggregates, as well as tangled clusters and crusts on the host rock.
Geological environment
## Genesis Adolfpateraite is a secondary mineral, forming in the oxidation zones of uranium deposits. It forms under post-magmatic conditions, as efflorescences on the walls of old tunnels and mine workings. Its formation is a result of the weathering of primary uranium ores (mainly uraninite) under the influence of sulfate-rich waters. ## Mineral Associations This mineral co-occurs with other secondary uranyl sulfates, such as uranopilite, johannite, as well as gypsum and schröckingerite. ## Localities The most important and type locality for adolfpateraite is Jáchymov (formerly St. Joachimsthal) in the Ore Mountains, Czech Republic. It is also known from the Lucky Mc mine in Fremont County, Wyoming (USA).
Rarity
Very rare
For collectors
## Quality Criteria The most valued specimens are those with well-formed, sharp crystals forming aesthetic, radial aggregates on a small rock matrix. Crystal size, color intensity, and richness of clusters significantly increase collectible value. Due to the rarity of the mineral, even microscopic but well-identified specimens are desirable. ## Popular Localities By far the most classic and sought-after specimens by collectors come from the type locality – Jáchymov in the Czech Republic. Material from this historic uranium mining area is the standard for this species.
Care and storage
## Cleaning Adolfpateraite specimens are very delicate and brittle. Only a soft brush or compressed air from a safe distance should be used for dust removal. Contact with water and any chemical agents should be avoided, as it is a sulfate and may dissolve or undergo chemical changes. ## What to Avoid The mineral is highly radioactive and should be handled with appropriate precautions. Direct, prolonged contact and inhalation of dust should be avoided. It is sensitive to shocks and mechanical damage. It should be protected from moisture and extreme temperatures. ## Storage It is recommended to store specimens in sealed, transparent containers (e.g., acrylic) that protect against damage and limit radon emission. Containers must be clearly marked with a radioactivity symbol. They should be kept in a location away from permanent human presence, preferably in a well-ventilated room.