Xanthoxenite is a rare secondary phosphate mineral found primarily in weathered granite pegmatites. Collectors usually search for its characteristic yellow, radiating, or platy crystal habit, which forms as an alteration product of primary phosphate minerals like triphylite.

Hardness
3.5
Mohs
Luster
Vitreous
Streak
White
Transparency
Translucent

Is this xanthoxenite?

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 xanthoxenite with a known reference. Xanthoxenite 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. Xanthoxenite leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Xanthoxenite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: yellow, brownish-yellow, yellowish-brown.
  • 5
    Look at form & habit
    Crystal system: triclinic. Typical habit: platy crystals, radial aggregates, crusts.

Often confused with

Xanthoxenite vs. its common look-alikes — and how to tell them apart in the field.

Often found alongside xanthoxenite

Minerals reported to co-occur with xanthoxenite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula
Ca₄Fe³⁺₂(PO₄)₄(OH)₂·3H₂O
Mohs hardness
3.5
Density
2.8 g/cm³
Streak
White
Luster
Vitreous
Transparency
Translucent
Crystal system
Triclinic
Crystal habit
Platy Crystals, Radial Aggregates, Crusts
Cleavage
Perfect in One Direction
Rarity
Rare
Uses
Collector
Host rock
Granite Pegmatites
Typical price
$50-300 per specimen

Where rockhounds find xanthoxenite

Classic worldwide localities

  • Hagendorf, Germany
  • Mangualde, Portugal
  • Tip Top mine, South Dakota, USA
  • Palermo No. 1 mine, New Hampshire, USA

Field-hunting tip

Look in granite pegmatites country — that is the host setting where xanthoxenite typically forms. If you start seeing triphylite, hureaulite, fairfieldite in float, you are in the right ground. Field specimens usually show a platy crystals, radial aggregates, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify xanthoxenite?+
Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, brownish-yellow, yellowish-brown.
Where is xanthoxenite found?+
Notable localities include Hagendorf, Germany; Mangualde, Portugal; Tip Top mine, South Dakota, USA; Palermo No. 1 mine, New Hampshire, USA.
How much is xanthoxenite 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 xanthoxenite?+
Xanthoxenite is most often confused with Rockbridgeite, Phosphosiderite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with xanthoxenite?+
Xanthoxenite commonly co-occurs with Triphylite, Hureaulite, Fairfieldite, Arrojadite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does xanthoxenite form in?+
Xanthoxenite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.
What is xanthoxenite used for?+
Xanthoxenite is used in collector.

Find xanthoxenite on the map

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