Clinofergusonite-(Ce) is a rare monoclinic rare-earth mineral belonging to the fergusonite group. It is typically found in rare-element granitic pegmatites, often occurring as dark, prismatic crystals that may appear resinous or subadamantine.

Hardness

5.5-6.5

Mohs

Luster

Subadamantine

Streak

Yellowish-grey

Transparency

Translucent

mineralrareFergusonite Group family

Clinofergusonite-(Ce)

Hardness: 5.5-6.5
Luster: Subadamantine
Streak: Yellowish-grey
Transparency: Translucent

No image

Is this clinofergusonite-(ce)?

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 clinofergusonite-(ce) with a known reference. Clinofergusonite-(Ce) sits at Mohs 5.5-6.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Clinofergusonite-(Ce) leaves a yellowish-grey streak.
3
Read the luster
Hold the specimen under a strong light. Clinofergusonite-(Ce) typically shows a subadamantine luster.
4
Match the color range
Compare against the expected color range: black, brown, yellowish-brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic, pyramidal, or massive.

Often confused with

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

mineral

Fergusonite-(Y)

Mohs 5.5-6.5

How to tell apart: Streak differs — Clinofergusonite-(Ce) leaves yellowish-grey, Fergusonite-(Y) leaves pale yellow; luster reads subadamantine on Clinofergusonite-(Ce) and vitreous on Fergusonite-(Y).

How to tell apart: Streak differs — Clinofergusonite-(Ce) leaves yellowish-grey, Samarskite-(Y) leaves dark brown; luster reads subadamantine on Clinofergusonite-(Ce) and submetallic on Samarskite-(Y).

Compare →

Often found alongside clinofergusonite-(ce)

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

All properties

Chemical formula: CeNbO₄
Mohs hardness: 5.5-6.5
Density: 5.8 g/cm³
Colors: Black Brown Yellowish-brown
Streak: Yellowish-grey
Luster: Subadamantine
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Prismatic, Pyramidal, Or Massive
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites and Alkaline Igneous Complexes
Typical price: $50-300 per specimen depending on size and crystal quality

Where rockhounds find clinofergusonite-(ce)

Classic worldwide localities

Kola Peninsula, Russia
Madagascar
Norway
Canada

Field-hunting tip

Look in granite pegmatites and alkaline igneous complexes country — that is the host setting where clinofergusonite-(ce) typically forms. If you start seeing zircon, apatite, allanite in float, you are in the right ground. Field specimens usually show a prismatic, pyramidal, or massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify clinofergusonite-(ce)?+

Mohs hardness is 5.5-6.5. It typically shows a subadamantine luster. The streak is yellowish-grey. Common colors include black, brown, yellowish-brown.

Where is clinofergusonite-(ce) found?+

Notable localities include Kola Peninsula, Russia; Madagascar; Norway; Canada.

How much is clinofergusonite-(ce) worth?+

Typical asking prices fall in the range of $50-300 per specimen depending on size and crystal quality. Quality, size, and provenance can move individual specimens well outside that range.

Is clinofergusonite-(ce) safe to handle?+

This mineral is radioactive. Contains rare earth elements and thorium impurities; handle with care and wash hands thoroughly after handling. Store in a dedicated mineral box away from other specimens and keep in an enclosed container to prevent inhalation of any potential decay dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like clinofergusonite-(ce)?+

Clinofergusonite-(Ce) is most often confused with Fergusonite-(Y), Samarskite-(Y). A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with clinofergusonite-(ce)?+

Clinofergusonite-(Ce) commonly co-occurs with Zircon, Apatite, Allanite, Microcline, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does clinofergusonite-(ce) form in?+

Clinofergusonite-(Ce) typically forms in granite pegmatites and alkaline igneous complexes. Working float back to the host body is the standard way to chase a fresh occurrence.

What is clinofergusonite-(ce) used for?+

Clinofergusonite-(Ce) is used in collector.

Find clinofergusonite-(ce) on the map

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