Formula: Li2SrAl4(PO4)4(OH)4
Anhydrous phosphate containing hydroxyl, palermoite group, forms a series with bertossaite, lithium- and strontium- bearing mineral
Specific gravity: 3.22
Hardness: 5½
Streak: White
Colour: Colourless, white, pale pink
Luminescence: Fluoresces white in direct X-ray beam (Mindat)

Hydrothermal environments


At the Carmo di Loano Mt., Toirano, Savona Province, Liguria, Italy, palermoite occurs near quartz veins in sandstones and conglomerates subjected to greenschist metamorphism. Associated minerals include lazulite, goyazite and brazilianite (HOM).

The type locality, the Palermo No. 1 Mine, Groton, Grafton county, New Hampshire, USA, is a complex zoned granite pegmatite. Palermoite occurs here in two paragenetic settings.
Paragenesis 1 consists of cavities in quartz veins extending from the pegmatite core into a first intermediate zone. Palermoite can be sprinkled randomly on the surfaces of quartz crystals lining voids in the vein. Associated species are few and include rare white pseudocubic goyazite to several millimeters and milky-white simple carbonate-rich fluorapatite crystals to 1 cm.
Paragenesis 2 consists of siderite and whitlockite replacements of triphylite in the first intermediate zone around the core. Siderite occurs as pale brown to amber-brown grains to 1 cm, sometimes coated with resinous olive-grey diadochite botryoids, much smaller than 1 mm. Whitlockite occurs as white masses interspersed with quartz and siderite; secondary whitlockite crystals, to several millimeters, occur in vugs in siderite.
Other early minerals in this paragenesis include doubly terminated quartz, compact kaolinite, brown childrenite crystals and white carbonate-rich fluorapatite.
Later minerals include palermoite, goyazite, crandallite, limonite, mitridatite, bjarebyite, goedkenite and hydroxylherderite.
Palermoite associates include pearly white thin platelets of goyazite, to 1 mm, that occur as interpenetrating intergrowths on palermoite and siderite; crandallite occurs as white to tan crystallised globules, to 1 mm, as a late-stage growth on palermoite; bjarebyite was also observed associated with palermoite.
Goedkenite appears to be distributed throughout paragenesis 2, but most palermoite shows no goedkenite in association; when it does occur, goedkenite is almost universally epitaxial to palermoite or goyazite, as colourless wedge-shaped tablets (R&M 77.4.240-241).
Palermoite crystals are typically transparent and colourless, 1 to 2 mm in size, and usually euhedral. Palermoite commonly occurs in isolated crystals, although two crystals in parallel growth are not uncommon (R&M 77.3.173).
Other reported associations at this locality include beraunite, and brazilianite (HOM).

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