Ferraioloite is a rare phosphate mineral discovered in the Mangualde pegmatite of Portugal. Collectors should look for its distinctive yellow, transparent platy crystals, which often form in radial clusters within cavities of weathered phosphate zones.
Is this ferraioloite?
4-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 ferraioloite with a known reference. Ferraioloite sits at Mohs ~2, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 3Match the color rangeCompare against the expected color range: greenish gray, lemon-yellow.
- 4Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, radial aggregates.
Often confused with
Ferraioloite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside ferraioloite
Minerals reported to co-occur with ferraioloite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MgMn²⁺₄(Fe²⁺₀.₅Al₀.₅)₄Zn₄(PO₄)₈(OH)₄(H₂O)₂₀
- Mohs hardness
- ~2
- Density
- 2.59 g/cm³
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Platy crystals, radial aggregates
- Cleavage
- Perfect on {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary phase in sugary pegmatite
Where rockhounds find ferraioloite
Classic worldwide localities
- Foote Lithium Company mine, Kings Mountain district, Cleveland County, North Carolina, USA
Field-hunting tip
Where it forms: A secondary phase in sugary pegmatite. If you start seeing vivianite, phosphophyllite, rittmannite in float, you are in the right ground. Typical habit: platy crystals, radial aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ferraioloite?+
Where is ferraioloite found?+
What rocks look like ferraioloite?+
What minerals are found with ferraioloite?+
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Find ferraioloite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
