Palermoite is a rare phosphate mineral typically found as small, clear, prismatic crystals or radial clusters within granite pegmatites. It is highly sought after by collectors of phosphate species and is most famously associated with the Palermo No. 1 Mine in New Hampshire.
Is this palermoite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch palermoite with a known reference. Palermoite sits at Mohs 5.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to subadamantine.
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: aggregates, fibrous.
Often confused with
Palermoite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside palermoite
Minerals reported to co-occur with palermoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Li₂SrAl₄(PO₄)₄(OH)₄
- Mohs hardness
- 5.5
- Density
- 3.22 g/cm³
- Streak
- White
- Luster
- Vitreous to subadamantine
- Transparency
- Semitransparent
- Crystal system
- Orthorhombic
- Crystal habit
- Aggregates, fibrous
- Cleavage
- On {001}, perfect; on {100}, fair
- Fluorescence
- White in direct x-ray beam under SW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A late hydrothermal product in a complex zoned granite pegmatite (Palermo #1 mine, New Hampshire, USA); near quartz veins in sandstones and conglomerates subjected to greenschist metamorphism (Giogo di Toirano, Italy)
Where rockhounds find palermoite
Classic worldwide localities
- Palermo #1 mine, near North Groton, Grafton Co., New Hampshire, USA
- Giogo di Toirano, near Bardineto, Liguria, Italy
- Xiyuantou pegmatite, Nanping, Fujian Province, China
Field-hunting tip
Where it forms: A late hydrothermal product in a complex zoned granite pegmatite (Palermo #1 mine, New Hampshire, USA); near quartz veins in sandstones and conglomerates subjected to greenschist metamorphism (Giogo di Toirano, Italy). If you start seeing siderite, childrenite–eosphorite, beraunite in float, you are in the right ground. Typical habit: aggregates, fibrous. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify palermoite?+
Where is palermoite found?+
What rocks look like palermoite?+
What minerals are found with palermoite?+
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Find palermoite on the map
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