Klajite is a rare manganese copper arsenate, typically greenish yellow to yellowish green. Associated minerals include enargite, quartz and gypsum. It was first described from Lejtakna area, Lahóca Hill, Recsk, Mátra Mountains, northern Hungary.

Hardness
2-3
Mohs
Luster
Vitreous
Streak
White
Transparency
Translucent

Is this klajite?

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 klajite with a known reference. Klajite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Klajite leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Klajite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: greenish yellow, yellowish green.
  • 5
    Look at form & habit
    Crystal system: triclinic. Typical habit: platy crystals, crusts, tabular aggregates.

Often confused with

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

Often found alongside klajite

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

All properties

Chemical formula
MnCu₄(AsO₄)₂(AsO₃OH)₂·9H₂O
Mohs hardness
2-3
Density
3.213 g/cm³
Streak
White
Luster
Vitreous
Transparency
Translucent
Crystal system
Triclinic
Crystal habit
Platy Crystals, Crusts, Tabular Aggregates
Cleavage
Perfect On {010}
Fluorescence
Bright Yellow-green Under UV
Rarity
Rare
Uses
Collector
Host rock
Hydrothermal Uranium Veins

Where rockhounds find klajite

Classic worldwide localities

  • Lejtakna area, Mátra Mountains, northern Hungary

Field-hunting tip

Look in hydrothermal uranium veins country, the host setting where klajite typically forms. If you start seeing uraninite, torbernite, autunite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, tabular aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify klajite?+
Mohs hardness is 2-3. It typically shows a vitreous luster. The streak is white. Common colors include greenish yellow, yellowish green.
Where is klajite found?+
Notable localities include Lejtakna area, Mátra Mountains, northern Hungary.
Is klajite safe to handle?+
This mineral is radioactive. It contains toxic constituents. Contains arsenic, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.
What rocks look like klajite?+
Klajite is most often confused with Autunite, Meta-autunite, Torbernite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with klajite?+
Klajite commonly co-occurs with Uraninite, Torbernite, Autunite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does klajite form in?+
Klajite typically forms in hydrothermal uranium veins. Working float back to the host body is the standard way to chase a fresh occurrence.
What is klajite used for?+
Klajite is used in collector.

Find klajite on the map

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