Pahasapaite
Chemical formula: Li₈(Ca,Li,K)₁₀.₅Be₂₄(PO₄)₂₄·38H₂O
Pahasaapaite is a very rare, hydrated lithium calcium beryllophosphate, forming tiny, vitreous crystals in the isometric system.
Properties
- Mohs hardness
- 4.5
- Color
- Colourless, light pink, yellow
- Luster
- Vitreous
- Streak
- White
- Density
- 2.28
- Cleavage
- None
- Fracture
- Irregular/Uneven
- Transparency
- Transparent
- Crystal system
- Isometric
Diagnostic features
## Identification Identifying pahasaapaite requires specialized equipment. Identification is based on the analysis of crystallographic form (small, isometric crystals), associated minerals, and confirmation of chemical composition using analytical methods such as EDS or XRD. Visually, it is practically impossible to distinguish from other colorless, microscopic minerals. ## Distinguishing from Similar Minerals It can be confused with other microscopic, colorless phosphate minerals found in pegmatites, such as wardite, montgomeryite, or childrenite. Definitive differentiation is only possible based on crystallographic and chemical analysis, as pahasaapaite crystallizes in the isometric system, which is rare in this group. ## Crystal Forms It forms very small, isometric crystals, mainly in the form of cubes and octahedra, as well as their combinations. Crystals are usually single and well-formed, rarely forming larger aggregates.
Geological environment
## Genesis Pahasaapaite is a hydrothermal mineral, crystallizing in the late stage of the evolution of complex granitic pegmatites. It forms in vugs and fractures as a result of alterations of earlier phosphate minerals. ## Mineral Associations It co-occurs with other rare phosphate minerals such as tiptopite, montgomeryite, wardite, roscherite, as well as with quartz, microcline, and muscovite. ## Localities The only confirmed locality of pahasaapaite in the world is its type locality – the Tip Top Mine near Custer, Custer County, South Dakota (USA).
Rarity
Extremely rare
For collectors
## Quality Criteria The quality of a pahasaapaite specimen is assessed based on the size and perfection of crystal development, although they are always microscopic. The most prized are sharp, vitreous, transparent cubes or octahedra, clearly standing out from the rock matrix. The aesthetics of the entire sample and the presence of other rare associated minerals are also important. ## Popular Localities The only source of specimens is the Tip Top Mine in South Dakota, USA. All pahasaapaite available on the collector's market originates from this single locality.
Care and storage
## Cleaning Specimens should only be cleaned with compressed air to remove dust. Due to the microscopic size of the crystals and their delicacy, any form of mechanical or chemical cleaning, including with water, is discouraged. ## What to Avoid Avoid contact with chemicals, acids, and detergents. The mineral is sensitive to changes in temperature and humidity, which can lead to its dehydration and damage. It should not be heated or exposed to ultrasound. ## Storage Pahasaapaite specimens, which are usually micromounts, should be stored under stable conditions, in closed, padded boxes that protect against dust, shocks, and sudden changes in temperature and humidity.