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Lussierite is an extremely rare sodium uranyl sulfate found almost exclusively in the alkaline rocks of the Poudrette Quarry. Collectors should look for thin, colorless to white tabular crystals that typically occur within small vugs in pegmatite or syenite host rocks.

Hardness
2
Mohs
Luster
Vitreous
Streak
White
Transparency
Transparent

Is this lussierite?

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 lussierite with a known reference. Lussierite sits at Mohs 2, softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Streak: white.
  • 3
    Read the luster
    Hold the specimen under a strong light. Luster: vitreous.
  • 4
    Match the color range
    Compare against the expected color range: pale green-yellow.
  • 5
    Look at form & habit
    Crystal system: monoclinic. Typical habit: tabular crystals.

Often confused with

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

Nahcolite mineral
mineral
Nahcolite
Mohs 2.5
Compare →

Often found alongside lussierite

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

All properties

Chemical formula
Na₁₀[(UO₂)(SO₄)₄](SO₄)₂(H₂O)₃
Mohs hardness
2
Density
2.87 g/cm³
Colors
Pale green-yellow
Streak
White
Luster
Vitreous
Transparency
Transparent
Crystal system
Monoclinic
Crystal habit
Tabular crystals
Cleavage
None
Rarity
Rare
Uses
Collector
Host rock
alkaline intrusive complexes

Where rockhounds find lussierite

Classic worldwide localities

  • Poudrette Quarry (Mont Saint-Hilaire, Quebec, Canada)

Field-hunting tip

Where it forms: alkaline intrusive complexes. If you start seeing glauberite, natrite, shortite in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lussierite?+
Mohs hardness is 2. Luster: vitreous. The streak is white. Common colors include pale green-yellow.
Where is lussierite found?+
Notable localities include Poudrette Quarry (Mont Saint-Hilaire, Quebec, Canada).
Is lussierite safe to handle?+
Lussierite contains uranium or thorium and calls for real care. Contains uranium; handle with gloves, avoid inhaling dust, wash hands thoroughly, and store away from other specimens.
What rocks look like lussierite?+
Lussierite is most often confused with Nahcolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with lussierite?+
Lussierite commonly co-occurs with glauberite, natrite, shortite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does lussierite form in?+
Where it forms: alkaline intrusive complexes. Working float back to the host body is the standard way to chase a fresh occurrence.
What is lussierite used for?+
Lussierite is used in collector.

Find lussierite on the map

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