Moraesite is a secondary phosphate mineral typically found as delicate, needle-like acicular crystals or fibrous radial tufts. It is primarily observed coating or replacing other beryllium minerals in zoned granite pegmatites.
Is this moraesite?
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 moraesite with a known reference. Moraesite 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: silky.
- 4Match the color rangeCompare against the expected color range: white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: druse, encrustations, spherical.
Often confused with
Moraesite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Moraesite leaves white, Veszelyite leaves green to white; luster reads silky on Moraesite and vitreous on Veszelyite.
How to tell apart: Hydroxylherderite is the harder of the two (Mohs 5-5.5 vs. 3); luster reads silky on Moraesite and vitreous to subvitreous, resinous on Hydroxylherderite.
Often found alongside moraesite
Minerals reported to co-occur with moraesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Be₂(PO₄)(OH)·4H₂O
- Mohs hardness
- 3
- Density
- 1.805 g/cm³
- Colors
- Streak
- White
- Luster
- Silky
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Druse, encrustations, spherical
- Cleavage
- Perfect, two directions yielding traces parallel [100] and [001] on {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare late-stage hydrothermal mineral in complex zoned granite pegmatites
Where rockhounds find moraesite
Classic worldwide localities
- Palermo #1 mine, near North Groton, Grafton Co., New Hampshire, USA
- Greenwood, in the Dunton quarry, Newry, and at Mt. Mica, near Paris, Oxford Co., Maine, USA
- Sapucaia pegmatite mine, about 50 km east-southeast of Governador Valadares, Brazil
- Mulundu and Humaita pegmatites, along the Jequitinhonha River, Itinga, and from the Almerindo pegmatite, Linópolis, Minas Gerais, Brazil
- Viitaniemi pegmatite, near Eräjärvi, Finland
- Arnac-la-Poste, Haute-Vienne, France
Field-hunting tip
Where it forms: A rare late-stage hydrothermal mineral in complex zoned granite pegmatites. If you start seeing beryl, beryllonite, hydroxylherderite in float, you are in the right ground. Typical habit: druse, encrustations, spherical. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify moraesite?+
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Find moraesite on the map
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