Landesite is a very rare secondary phosphate mineral found primarily in complex granite pegmatites. It typically forms as a weathering product of manganese-rich phosphates, often appearing as yellowish-brown platy crystals or as micaceous crusts.
Is this landesite?
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 landesite with a known reference. Landesite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Landesite leaves a yellowish-white streak.
- 3Read the lusterHold the specimen under a strong light. Landesite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellowish-brown, brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy or micaceous aggregates.
Often confused with
Landesite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside landesite
Minerals reported to co-occur with landesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mn²⁺₅(PO₄)₂(OH)₄·8H₂O
- Mohs hardness
- 3.5
- Density
- 3.1 g/cm³
- Colors
- Streak
- Yellowish-white
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy or Micaceous Aggregates
- Cleavage
- Perfect in One Direction
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
- Typical price
- $50-300 per specimen
Where rockhounds find landesite
Classic worldwide localities
- Poland Mine, Maine, USA
Field-hunting tip
Look in granite pegmatites country — that is the host setting where landesite typically forms. If you start seeing dickinsonite, eosphorite, fairfieldite in float, you are in the right ground. Field specimens usually show a platy or micaceous aggregates habit, so train your eye for that shape before scanning the outcrop.



