Steenstrupine-(Ce) is a rare complex silicate mineral primarily known from highly alkaline igneous complexes. It typically forms as dark, tabular rhombohedral crystals and is noted for its significant radioactive content due to thorium and uranium inclusion.

Hardness

Mohs

Luster

Vitreous

Streak

Yellowish Brown

Transparency

Translucent

mineralrare

Steenstrupine-(Ce)

Hardness: 4
Luster: Vitreous
Streak: Yellowish Brown
Transparency: Translucent

Is this steenstrupine-(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 steenstrupine-(ce) with a known reference. Steenstrupine-(Ce) sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Steenstrupine-(Ce) leaves a yellowish brown streak.
3
Read the luster
Hold the specimen under a strong light. Steenstrupine-(Ce) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: brown, black, yellow, pink, red.
5
Look at form & habit
Crystal system: trigonal. Typical habit: tabular rhombohedral crystals.

Often confused with

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

mineral

Monazite

Mohs 5-5.5

How to tell apart: Monazite is the harder of the two (Mohs 5-5.5 vs. 4); streak differs — Steenstrupine-(Ce) leaves yellowish brown, Monazite leaves white; luster reads vitreous on Steenstrupine-(Ce) and resinous on Monazite.

How to tell apart: Eudialyte is the harder of the two (Mohs 5-6 vs. 4); streak differs — Steenstrupine-(Ce) leaves yellowish brown, Eudialyte leaves white.

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Often found alongside steenstrupine-(ce)

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

All properties

Chemical formula: Na₁₄Ce₆Mn₂Fe₂Zr(PO₄)₇Si₁₂O₃₆(OH)₂·3H₂O
Mohs hardness: 4
Density: 3.3-3.5 g/cm³
Colors: Brown Black Yellow Pink Red
Streak: Yellowish Brown
Luster: Vitreous
Transparency: Translucent
Crystal system: Trigonal
Crystal habit: Tabular Rhombohedral Crystals
Cleavage: Poor
Rarity: Rare
Uses: Collector
Host rock: Alkaline Igneous Rocks
Typical price: $50-500 depending on specimen size and radioactivity levels

Where rockhounds find steenstrupine-(ce)

Classic worldwide localities

Ilimaussaq complex, Greenland
Kola Peninsula, Russia

Field-hunting tip

Look in alkaline igneous rocks country — that is the host setting where steenstrupine-(ce) typically forms. If you start seeing eudialyte, aegirine, arfvedsonite in float, you are in the right ground. Field specimens usually show a tabular rhombohedral crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify steenstrupine-(ce)?+

Mohs hardness is 4. It typically shows a vitreous luster. The streak is yellowish brown. Common colors include brown, black, yellow, pink.

Where is steenstrupine-(ce) found?+

Notable localities include Ilimaussaq complex, Greenland; Kola Peninsula, Russia.

How much is steenstrupine-(ce) worth?+

Typical asking prices fall in the range of $50-500 depending on specimen size and radioactivity levels. Quality, size, and provenance can move individual specimens well outside that range.

Is steenstrupine-(ce) safe to handle?+

This mineral is radioactive. This mineral is radioactive and should be handled with care. Store in a labeled, lead-lined or secure container, minimize direct skin contact, and avoid inhaling dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like steenstrupine-(ce)?+

Steenstrupine-(Ce) is most often confused with Monazite, Eudialyte. A quick hardness test and a streak check separate the look-alikes faster than color alone.

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

Steenstrupine-(Ce) commonly co-occurs with Eudialyte, Aegirine, Arfvedsonite, Nepheline. Spotting any of these in float or country rock is a useful trip signal.

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

Steenstrupine-(Ce) typically forms in alkaline igneous rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is steenstrupine-(ce) used for?+

Steenstrupine-(Ce) is used in collector.

Find steenstrupine-(ce) on the map

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