Lacroixite

minerals

morinite

childrenite

roscherite

Formula: NaAl(PO4)F
Anhydrous phosphate containing halogen
Specific gravity: 3.126 to 3.29
Hardness: 4½
Streak: White
Colour: Colourless, light yellow, light green, almost white, colourless in transmitted light
Solubility: Readily soluble in hydrochloric and sulphuric acid
Environments

Pegmatites

Lacroixite frequently occurs as grains and rods in the altered margins of amblygonite or montebrasite embedded in a granite pegmatite matrix (Mindat).

Localities

At the type locality, the Greifenstein Rocks, Ehrenfriedersdorf, Erzgebirgskreis, Saxony, Germany, lacroixite occurs in a lithium-bearing granite pegmatite intimately mixed with its alteration product viitaniemiite and associated with muscovite, morinite, ježekite, fluorapatite, childrenite, roscherite, feldspar, elbaite and quartz (HOM, Dana, Mindat).

At the Rusororo pegmatite, Gatumba, Ngororero District, Western Province, Rwanda, lacroixite occurs as an alteration product in a complex granite pegmatite, associated with montebrasite, scorzalite and berlinite (HOM).

At the Strickland Quarry, Strickland pegmatite, Collins Hill, Portland, Middlesex county, Connecticut, USA, lacroixite is associated with apatite, augelite and brazilianite (HOM).

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