Attakolite

Overview

Attakolite is a rare calcium-manganese-aluminium silico-phosphate mineral known almost exclusively from a single Swedish locality. Its name derives from the Greek attakos, meaning salmon, in reference to its characteristic pale pink to salmon colour. First found at the Västanå iron mine in Skåne, southern Sweden, it is a collector rarity rather than an ore or ornamental stone and is valued chiefly for its scientific and historical interest.

Composition & structure

Modern analysis shows attakolite is a silico-phosphate rather than a simple phosphate: the accepted formula is CaMn²⁺Al₄(HSiO₄)(PO₄)₃(OH)₄, combining phosphate and a silicate group in one structure, with strontium able to substitute for some calcium. It crystallises in the monoclinic system and typically occurs as compact masses and small grains rather than large free-standing crystals. The mix of divalent manganese, aluminium, phosphate and silicate reflects the unusual aluminous, phosphate-rich rocks in which it formed.

Formation & occurrence

Attakolite formed in the aluminous, phosphate-bearing metamorphic rocks of the Västanå iron deposit, which is famous among mineralogists as the type locality for several phosphate and related minerals, including augelite, berlinite and trolleite. There it occurs with a distinctive suite of aluminium phosphates and sulfates such as svanbergite, lazulite and trolleite, alongside hematite and other accessory minerals. These associations point to formation under conditions rich in phosphorus and aluminium but poor in silica-dominated rock-forming minerals.

Identification & similar species

The salmon-pink colour that gives attakolite its name is its most memorable feature, but reliable identification needs laboratory analysis because several pink aluminium phosphates look similar. Its moderate hardness of about 5 and vitreous-to-greasy lustre help, yet it can resemble associated species such as lazulite or svanbergite in hand specimen. Chemistry and X-ray data, particularly the presence of the silicate group, are what confirm it.

Notable localities & collecting

Attakolite is essentially confined to its Västanå type locality, where the mine operated from the early nineteenth century into the early twentieth. A handful of comparable phosphate occurrences elsewhere have been noted, but Swedish material remains the reference standard and the source of nearly all specimens. Because the mine is long closed and the mineral was never common, attakolite is a genuine rarity, and specimens are encountered mainly in established collections and specialist dealers rather than on the general market.