Attakolite
Chemical formula: CaMn²⁺Al₄(HSiO₄)(PO₄)₃(OH)₄
Attakolite is a very rare, reddish-brown phosphate mineral, found as small aggregates in granitic pegmatites.
Properties
- Mohs hardness
- 5
- Color
- Pale red, white to pink
- Luster
- Vitreous to greasy
- Streak
- Light brown
- Density
- 3.09
- Cleavage
- Imperfect on {100}
- Fracture
- Uneven
- Transparency
- Transparent
- Crystal system
- Monoclinic
Diagnostic features
## Identification Identifying attakolite is extremely difficult and practically impossible without advanced analytical methods such as X-ray diffraction (XRD) or chemical analysis (EDS/WDS). In field conditions or in a collection, identification relies mainly on a label from a confirmed locality. Its reddish-brown color and occurrence in association with other rare phosphates in pegmatites can be a clue. ## Distinguishing from Similar Minerals It can be confused with many other reddish or brown granular minerals found in pegmatites, such as eudialyte, some garnets (spessartine), or even apatite. Visual distinction is practically impossible; it requires specialized laboratory tests. ## Crystal Forms Attakolite primarily forms massive, cryptocrystalline, or fine-grained aggregates. Very rarely, poorly developed, tabular crystals not exceeding fractions of a millimeter are observed.
Geological environment
## Genesis Attakolite is a hydrothermal mineral, crystallizing in the late stages of the evolution of complex granitic pegmatites, rich in phosphorus and manganese. It forms as a result of metasomatic alterations of earlier phosphate minerals. ## Mineral Associations This mineral co-occurs with other rare phosphates. In its type locality (Västanå, Sweden), it was found in association with minerals such as augelite, lazulite, svanbergite, trolleite, gatumbaite, and apatite. It also occurs in association with quartz. ## Localities Confirmed occurrences of attakolite are extremely rare. Besides the type locality in the Västanå mine in Scania (Sweden), it has only been identified in the Córrego do Urucum pegmatite in Minas Gerais (Brazil) and in the Messeres quarry in the Beira Alta province (Portugal).
Rarity
Very rare
For collectors
## Quality Criteria Due to its extreme rarity, every analytically confirmed attakolite specimen is valuable to specialized collectors. Most highly prized are specimens where attakolite forms the richest possible aggregates with an intense, reddish-brown color, clearly visible against the matrix rock. The presence of rare associated minerals, especially from the type locality, significantly increases the scientific and collectible value of the specimen. ## Popular Localities The only source of specimens of collectible significance is the historical type locality – the Västanå mine in Sweden. Material from this location is extremely difficult to acquire and appears on the market sporadically, mainly through the redistribution of old collections.
Care and storage
## Cleaning Due to the extreme rarity and typically small size of specimens, mechanical cleaning is highly inadvisable. If absolutely necessary, compressed air can be used to remove dust. Avoid contact with water and any chemicals. ## What to Avoid Avoid ultrasonics, steam cleaners, acids, and all chemical solvents. The mineral is sensitive to chemical action and can be damaged. It should also be protected from high temperatures and sudden temperature changes. ## Storage Attakolite specimens should be stored under stable conditions, in a closed display box, away from light, dust, and moisture. It is best to keep it in its original labeled container to avoid confusion with other, more common minerals.