Natrosulfatourea
Chemical formula: Na₂(S⁶⁺O₄)[CO(N³⁻H₂)₂]
Natrosulfatourea is a rare, organic salt mineral, a naturally occurring combination of sodium sulfate and urea.
Properties
- Mohs hardness
- 1.5
- Color
- colourless
- Luster
- Vitreous
- Streak
- white
- Density
- 1.97
- Cleavage
- on {100}
- Fracture
- Irregular/Uneven
- Transparency
- Transparent
- Crystal system
- Orthorhombic
Diagnostic features
## Identification A key diagnostic feature is its extreme sensitivity to moisture and solubility in water. In field conditions, its disappearance under the influence of rain or even high air humidity can be observed. In a collection, identification is confirmed by the crystal habit and storage conditions. ## Differentiation from Similar Minerals It can be confused with other water-soluble sulfates or nitrates that form similar efflorescences, e.g., halotrichite or mirabilite. Differentiation requires advanced research, such as X-ray diffraction (XRD), due to its unique crystal structure. ## Crystal Forms It forms elongated, prismatic to acicular crystals, often gathered in radial or chaotic aggregates. It also occurs as thin efflorescences and crusts.
Geological environment
## Genesis Natrosulfatourea is a mineral of anthropogenic origin. It forms as a result of the reaction of urea-containing solutions with sulfate minerals. Its formation is associated with industrial activity, e.g., in mine dumps, where waste containing nitrogen compounds (from explosives) interacts with sulfates. ## Mineral Associations At the type locality (Kola Peninsula), it co-occurs with thenardite, natron, thermonatrite, and urea sulfate (another mineral from this group). ## Localities The only confirmed locality for this mineral in the world is the burning coal mine dump No. 45 near the city of Kopeysk, in the Chelyabinsk Oblast in the Southern Urals, Russia. The Kola Peninsula was initially incorrectly reported as the discovery site.
Rarity
Extremely rare
For collectors
## Quality Criteria Due to its extreme rarity and instability, any well-formed and properly secured specimen is valuable. The most desirable specimens are those with visible, sharp prismatic crystals, preferably in the form of rich aggregates on a small fragment of the host rock. The size of the crystals (even 1-2 mm) significantly increases the value of the specimen. ## Popular Localities The only source of collector specimens is the burning mine dump in Kopeysk, Russia. Material from this location is extremely difficult to obtain and secure.
Care and storage
## Cleaning The mineral is extremely sensitive to water and moisture. It should not be cleaned wet. Only very careful, mechanical removal of dust with a soft brush or a stream of compressed air from a distance is permissible. ## What to Avoid Avoid all contact with water, water vapor, and other liquids, which will cause its immediate dissolution. The mineral is hygroscopic, so it must be protected from humid air. It should not be heated or exposed to temperature changes. ## Storage Natrosulfatourea specimens require storage in hermetic conditions. The best solution is a sealed container (e.g., a "perky box") with a desiccant (silica gel). It should be kept away from sources of heat and moisture.