Faheyite is a rare phosphate mineral primarily found in complex granite pegmatites. It typically occurs as small, delicate clusters of fibrous or acicular crystals and is highly prized by micromount collectors due to its scarcity and distinct habit.
Is this faheyite?
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 faheyite with a known reference. Faheyite sits at Mohs 3, 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.
- 4Match the color rangeCompare against the expected color range: white, blue white, brownish white.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: fibrous, acicular, prismatic.
Often confused with
Faheyite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Roscherite is the harder of the two (Mohs 4.5 vs. 3); streak differs, so Faheyite leaves white, Roscherite leaves light brown.
How to tell apart: Streak differs, so Faheyite leaves white, Hureaulite leaves nearly white.
Often found alongside faheyite
Minerals reported to co-occur with faheyite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Be₂MnFe₂(PO₄)₄·6H₂O
- Mohs hardness
- 3
- Density
- 2.660 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Hexagonal
- Crystal habit
- Fibrous, acicular, prismatic
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare late-stage secondary mineral in a complex granite pegmatite (Sapucaia mine, Brazil)
Where rockhounds find faheyite
Classic worldwide localities
- Roosevelt mine, near Custer, Custer Co., South Dakota, USA
- Sapucaia pegmatite mine, about 50 km east-southeast of Governador Valadares, Minas Gerais, Brazil
- Noumas mine, Blesberg, Cape Province, South Africa
Field-hunting tip
Where it forms: A rare late-stage secondary mineral in a complex granite pegmatite (Sapucaia mine, Brazil). If you start seeing quartz, muscovite, variscite in float, you are in the right ground. Typical habit: fibrous, acicular, prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify faheyite?+
Where is faheyite found?+
Is faheyite safe to handle?+
What rocks look like faheyite?+
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Find faheyite on the map
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