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.

Hardness
3.5
Mohs
Luster
Vitreous
Streak
Yellowish-white
Transparency
Translucent

Is this landesite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try to scratch landesite with a known reference. Landesite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Landesite leaves a yellowish-white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Landesite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: yellowish-brown, brown.
  • 5
    Look at form & habit
    Crystal 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
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.

Common questions

How do you identify landesite?+
Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is yellowish-white. Common colors include yellowish-brown, brown.
Where is landesite found?+
Notable localities include Poland Mine, Maine, USA.
How much is landesite worth?+
Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like landesite?+
Landesite is most often confused with Fairfieldite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with landesite?+
Landesite commonly co-occurs with Dickinsonite, Eosphorite, Fairfieldite, Triphylite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does landesite form in?+
Landesite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.
What is landesite used for?+
Landesite is used in collector.

Find landesite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.

Download on the App StoreGet it on Google Play