Walentaite is an extremely rare iron arsenate-phosphate mineral that typically forms as delicate, platy crystals or radial clusters. It is primarily found in the oxidation zones of complex granite pegmatites and is a prized target for advanced mineral collectors due to its scarcity and unique crystal form.
Is this walentaite?
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 walentaite with a known reference. Walentaite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Walentaite leaves a pale yellow streak.
- 3Read the lusterHold the specimen under a strong light. Walentaite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: bright yellow, bright greenish yellow, pale brownish.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, radial aggregates.
Often confused with
Walentaite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Walentaite leaves pale yellow, Pharmacosiderite leaves yellowish green; luster reads vitreous on Walentaite and adamantine on Pharmacosiderite.
How to tell apart: Scorodite is the harder of the two (Mohs 3.5-4 vs. 2.5); streak differs, so Walentaite leaves pale yellow, Scorodite leaves white; luster reads vitreous on Walentaite and vitreous to subadamantine on Scorodite.
Often found alongside walentaite
Minerals reported to co-occur with walentaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- H₄Fe³⁺₃(AsO₄)₂PO₄·4H₂O
- Mohs hardness
- 2.5
- Density
- 2.72 g/cm³
- Streak
- Pale Yellow
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy Crystals, Radial Aggregates
- Cleavage
- Perfect On {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
Where rockhounds find walentaite
Classic worldwide localities
- Hagendorf-Sud Pegmatite, Bavaria, Germany
- Tip Top Mine, South Dakota, USA
- Reaphook Hill, South Australia
Field-hunting tip
Look in granite pegmatites country, the host setting where walentaite typically forms. If you start seeing arsenopyrite, phosphosiderite, strengite in float, you are in the right ground. Field specimens usually show a platy crystals, radial aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify walentaite?+
Where is walentaite found?+
Is walentaite safe to handle?+
What rocks look like walentaite?+
What minerals are found with walentaite?+
What kind of rock does walentaite form in?+
What is walentaite used for?+
Find walentaite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
