Carlgieseckeite-(Nd) is an extremely rare carbonate mineral found primarily in the agpaitic rocks of the Ilímaussaq complex. It typically appears as small, reddish-brown platy crystals associated with complex alkaline pegmatites. Collectors prize it for its unique chemical composition featuring neodymium as the dominant rare earth element.

Hardness

4-5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareTundrite Group family

Carlgieseckeite-(Nd)

Hardness: 4-5
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this carlgieseckeite-(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 carlgieseckeite-(nd) with a known reference. Carlgieseckeite-(Nd) sits at Mohs 4-5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Carlgieseckeite-(Nd) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Carlgieseckeite-(Nd) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: reddish-brown, brown.
5
Look at form & habit
Crystal system: triclinic. Typical habit: platy crystals.

Often found alongside carlgieseckeite-(nd)

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

All properties

Chemical formula: Na(Nd,Ce)₄(CO₃)₃F(OH)₂
Mohs hardness: 4-5
Density: 4.57 g/cm³
Colors: Reddish-brown Brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Platy Crystals
Cleavage: Good
Rarity: Rare
Uses: Collector
Host rock: Nepheline Syenite Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find carlgieseckeite-(nd)

Classic worldwide localities

Ilímaussaq complex, Greenland

Field-hunting tip

Look in nepheline syenite pegmatites country — that is the host setting where carlgieseckeite-(nd) typically forms. If you start seeing aegirine, microcline, arfvedsonite in float, you are in the right ground. Field specimens usually show a platy crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify carlgieseckeite-(nd)?+

Mohs hardness is 4-5. It typically shows a vitreous luster. The streak is white. Common colors include reddish-brown, brown.

Where is carlgieseckeite-(nd) found?+

Notable localities include Ilímaussaq complex, Greenland.

How much is carlgieseckeite-(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.

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

Carlgieseckeite-(Nd) commonly co-occurs with Aegirine, Microcline, Arfvedsonite. Spotting any of these in float or country rock is a useful trip signal.

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

Carlgieseckeite-(Nd) typically forms in nepheline syenite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is carlgieseckeite-(nd) used for?+

Carlgieseckeite-(Nd) is used in collector.

Find carlgieseckeite-(nd) on the map

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