Wilhelmvierlingite is a rare phosphate mineral typically found as small, thin plates or radiating groups within phosphate-rich pegmatites. It is most recognized from the Hagendorf-South locality in Germany where it occurs as a secondary mineral during the alteration of primary phosphate species.
Is this wilhelmvierlingite?
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 wilhelmvierlingite with a known reference. Wilhelmvierlingite sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Wilhelmvierlingite leaves a yellowish white streak.
- 3Read the lusterHold the specimen under a strong light. Wilhelmvierlingite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, brownish yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, radial aggregates.
Often confused with
Wilhelmvierlingite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Childrenite is the harder of the two (Mohs 5 vs. 4); streak differs — Wilhelmvierlingite leaves yellowish white, Childrenite leaves white; luster reads vitreous on Wilhelmvierlingite and vitreous to resinous on Childrenite.
How to tell apart: Eosphorite is the harder of the two (Mohs 5 vs. 4); streak differs — Wilhelmvierlingite leaves yellowish white, Eosphorite leaves white.
Often found alongside wilhelmvierlingite
Minerals reported to co-occur with wilhelmvierlingite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaMn²⁺Fe²⁺₂(PO₄)₂(OH)₂·2H₂O
- Mohs hardness
- 4
- Density
- 3.31 g/cm³
- Colors
- Streak
- Yellowish White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy Crystals, Radial Aggregates
- Cleavage
- None Observed
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
- Typical price
- $50-300 per specimen
Where rockhounds find wilhelmvierlingite
Classic worldwide localities
- Hagendorf-South pegmatite, Bavaria, Germany
- Mangualde, Portugal
Field-hunting tip
Look in granite pegmatites country — that is the host setting where wilhelmvierlingite typically forms. If you start seeing triphylite, ludlamite, vivianite 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 wilhelmvierlingite?+
Where is wilhelmvierlingite found?+
How much is wilhelmvierlingite worth?+
What rocks look like wilhelmvierlingite?+
What minerals are found with wilhelmvierlingite?+
What kind of rock does wilhelmvierlingite form in?+
What is wilhelmvierlingite used for?+
Find wilhelmvierlingite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
