Klaprothite is a rare sodium uranium sulfate, typically yellowish green to greenish yellow. It was approved as a distinct mineral species in 2015. It was first described from Blue Lizard mine, Red Canyon, White Canyon district, San Juan County, Utah, USA.

Hardness
2.5
Mohs
Luster
Vitreous
Streak
Pale Yellow-green
Transparency
Transparent

Is this klaprothite?

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 klaprothite with a known reference. Klaprothite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Klaprothite leaves a pale yellow-green streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Klaprothite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: yellowish green, greenish yellow.
  • 5
    Look at form & habit
    Crystal system: monoclinic. Typical habit: massive, granular, or rarely as indistinct prismatic crystals.

Often confused with

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

Often found alongside klaprothite

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

All properties

Chemical formula
Na₆(UO₂)(SO₄)₄(H₂O)₄
Mohs hardness
2.5
Density
2.90 g/cm³
Streak
Pale Yellow-green
Luster
Vitreous
Transparency
Transparent
Crystal system
Monoclinic
Crystal habit
Massive, Granular, Or Rarely as Indistinct Prismatic Crystals
Cleavage
Perfect On {100} and {001}
Rarity
Rare
Uses
Collector
Host rock
Hydrothermal Veins

Where rockhounds find klaprothite

Classic worldwide localities

  • Blue Lizard mine, Utah, USA

Field-hunting tip

Look in hydrothermal veins country, the host setting where klaprothite typically forms. If you start seeing wittichenite, bismuthinite, chalcopyrite in float, you are in the right ground. Field specimens usually show a massive, granular, or rarely as indistinct prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify klaprothite?+
Mohs hardness is 2.5. It typically shows a vitreous luster. The streak is pale yellow-green. Common colors include yellowish green, greenish yellow.
Where is klaprothite found?+
Notable localities include Blue Lizard mine, Utah, USA.
Is klaprothite safe to handle?+
This mineral is radioactive. It contains toxic constituents. Contains uranium and is radioactive; store it apart from other specimens. Wash hands thoroughly after handling and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.
What rocks look like klaprothite?+
Klaprothite is most often confused with Wittichenite, Tetrahedrite, Bismuthinite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with klaprothite?+
Klaprothite commonly co-occurs with Wittichenite, Bismuthinite, Chalcopyrite, Bornite, Galena. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does klaprothite form in?+
Klaprothite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.
What is klaprothite used for?+
Klaprothite is used in collector.

Find klaprothite 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