Mangazeite
Chemical formula: Al₂S⁶⁺O₄(OH)₄·3H₂O
Mangazeite is a very rare, hydrated aluminum sulfate, forming small, colorless or white crystals with a platy or lath-like habit.
Properties
- Mohs hardness
- 1-2
- Color
- Pale yellowish, white, colorless
- Luster
- Vitreous
- Streak
- White
- Density
- 0
- Cleavage
- Perfect on {100}
- Fracture
- Uneven
- Transparency
- Transparent
- Crystal system
- Triclinic
Diagnostic features
## Identification Identification of mangazeite is possible almost exclusively through advanced analytical methods, such as X-ray diffraction (XRD) and chemical analysis (EDS/WDS). Visually, at the occurrence site, it can be suspected based on the formation of small, colorless, platy crystals in radial aggregates in volcanic fumarole environments. ## Distinguishing from Similar Minerals Mangazeite can be confused with other volcanic sublimation products, such as potassium alum, sassolite, or other rare sulfates. Certain differentiation from these minerals requires specialized laboratory equipment. ## Crystal Forms It forms elongated, lath-like or thin, platy crystals, flattened parallel to the {100} plane. These crystals often combine into radial or stellate aggregates and thin coatings.
Geological environment
## Genesis Mangazeite is a mineral of volcanic origin. It forms as a result of fumarolic activity, which is the exhalation of hot volcanic gases. It crystallizes directly from the gas phase (sublimation) at temperatures of approximately 100-120°C, depositing on the surface of volcanic rocks, such as andesites. ## Mineral Associations It co-occurs with other fumarolic minerals, such as potassium alum, anhydrite, gypsum, sassolite, and rare aluminum sulfates, e.g., alumohydrocalcite. ## Localities The only confirmed locality of this mineral in the world (type locality) is the fumaroles of Mangazeia volcano, located on Paramushir Island in the Kuril Islands archipelago (Sakhalin Oblast, Russia).
Rarity
Extremely rare
For collectors
## Quality Criteria As a "micromount" type mineral, with scientific value, the only evaluation criterion is the quality and abundance of crystals visible under a microscope on a fragment of the host rock. The most desirable specimens are those with well-formed, distinct crystals forming aesthetic aggregates. Identification must be analytically confirmed. ## Popular Localities The only source of specimens is the type locality in Russia. Availability on the collector's market is practically zero, and specimens are mainly found in the collections of scientific institutions.
Care and storage
## Cleaning Due to its extreme rarity, fragility, and small crystal size, mechanical cleaning is highly inadvisable. Specimens should be protected from dust in sealed containers and do not require cleaning. ## What to Avoid Avoid contact with water, chemicals, as well as any vibrations and impacts. The mineral is very delicate. Protect it from high temperatures, which can cause the loss of water from its structure (dehydration). ## Storage Mangazeite specimens should be stored exclusively in specialized, sealed "micromount" boxes, protecting them from dust, moisture, and mechanical damage. It is not suitable for display outside such protection.