Planerite is a relatively rare hydrated aluminum phosphate mineral that typically forms as botryoidal crusts or radial aggregates. Collectors often find it as a secondary mineral in phosphate-rich environments, frequently associated with variscite and wavellite. It is best identified by its distinct habit and occurrence within weathered aluminum-bearing phosphate deposits.
Is this planerite?
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 planerite with a known reference. Planerite 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. Planerite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Planerite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, blue, green, yellow.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: botryoidal, crusts, radial aggregates.
Often confused with
Planerite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Luster reads vitreous on Planerite and waxy on Variscite.
How to tell apart: Wardite is the harder of the two (Mohs 5 vs. 4).
How to tell apart: Crandallite is the harder of the two (Mohs 5 vs. 4).
Often found alongside planerite
Minerals reported to co-occur with planerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₆(PO₄)₄(OH)₆·10H₂O
- Mohs hardness
- 4
- Density
- 2.81 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Tetragonal
- Crystal habit
- Botryoidal, Crusts, Radial Aggregates
- Cleavage
- Good
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Phosphate-rich Hydrothermal Veins and Secondary Oxidation Zones
- Typical price
- $20-150 for small specimens
Where rockhounds find planerite
Classic worldwide localities
- Dalnegorsk, Russia
- Dodford, England
- Montebras, France
- Montgomery County, Arkansas, USA
Field-hunting tip
Look in phosphate-rich hydrothermal veins and secondary oxidation zones country — that is the host setting where planerite typically forms. If you start seeing variscite, wavellite, crandallite in float, you are in the right ground. Field specimens usually show a botryoidal, crusts, radial aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify planerite?+
Where is planerite found?+
How much is planerite worth?+
What rocks look like planerite?+
What minerals are found with planerite?+
What kind of rock does planerite form in?+
What is planerite used for?+
Find planerite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
