Françoisite-(Nd) is a very rare secondary uranium mineral typically found in the oxidized zones of uranium-rich ore bodies. It usually occurs as small, yellow, platy crystals or thin crusts, often associated with other uranium-bearing minerals.

Hardness

Mohs

Luster

Dull

Streak

Yellow

Transparency

Translucent

mineralrare

Françoisite-(Nd)

Hardness: 3
Luster: Dull
Streak: Yellow
Transparency: Translucent

Is this françoisite-(nd)?

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 françoisite-(nd) with a known reference. Françoisite-(Nd) sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Françoisite-(Nd) leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Françoisite-(Nd) typically shows a dull luster.
4
Match the color range
Compare against the expected color range: yellow, yellowish-orange.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals, crusts, radial aggregates.

Often confused with

Françoisite-(Nd) vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Luster reads dull on Françoisite-(Nd) and pearly on Françoisite-(Ce).

How to tell apart: Luster reads dull on Françoisite-(Nd) and pearly on Meta-autunite.

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Often found alongside françoisite-(nd)

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

All properties

Chemical formula: (Nd,Sm,Gd)(UO₂)₃(PO₄)₂(OH)₃·8H₂O
Mohs hardness: 3
Density: 4.45 g/cm³
Colors: Yellow Yellowish-orange
Streak: Yellow
Luster: Dull
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Platy Crystals, Crusts, Radial Aggregates
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Uranium Deposits
Typical price: $50-300 per specimen

Where rockhounds find françoisite-(nd)

Classic worldwide localities

Masupa-Kabwe, Democratic Republic of the Congo
Lodève, France

Field-hunting tip

Look in oxidized zones of uranium deposits country — that is the host setting where françoisite-(nd) typically forms. If you start seeing uraninite, parsonsite, torbernite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, radial aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify françoisite-(nd)?+

Mohs hardness is 3. It typically shows a dull luster. The streak is yellow. Common colors include yellow, yellowish-orange.

Where is françoisite-(nd) found?+

Notable localities include Masupa-Kabwe, Democratic Republic of the Congo; Lodève, France.

How much is françoisite-(nd) 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.

Is françoisite-(nd) safe to handle?+

This mineral is radioactive. It contains toxic constituents. Contains uranium and is radioactive; handle with gloves and wash hands thoroughly after handling. Store in a lead-lined container or away from human living spaces to minimize radon exposure and radiation. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like françoisite-(nd)?+

Françoisite-(Nd) is most often confused with Françoisite-(Ce), Meta-autunite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with françoisite-(nd)?+

Françoisite-(Nd) commonly co-occurs with Uraninite, Parsonsite, Torbernite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does françoisite-(nd) form in?+

Françoisite-(Nd) typically forms in oxidized zones of uranium deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is françoisite-(nd) used for?+

Françoisite-(Nd) is used in collector.

Find françoisite-(nd) on the map

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