Tundrite-(Nd) is a rare silicate-carbonate mineral primarily found in the complex alkaline rocks of the Kola Peninsula in Russia. It typically occurs as small, tabular, or platy crystals associated with other rare earth minerals in pegmatite veins.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Semitransparent

mineralrareTundrite Group family

Tundrite-(Nd)

Hardness: 3
Luster: Vitreous
Streak: White
Transparency: Semitransparent

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Is this tundrite-(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 tundrite-(nd) with a known reference. Tundrite-(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. 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: yellow, greenish yellow.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals, thin plates.

Often confused with

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

mineral

Tundrite-(Ce)

Mohs ~3

How to tell apart: Streak differs, so Tundrite-(Nd) leaves white, Tundrite-(Ce) leaves yellowish gray to white.

How to tell apart: Lorenzenite is the harder of the two (Mohs 6 vs. 3); streak differs, so Tundrite-(Nd) leaves white, Lorenzenite leaves light brownish yellow.

Compare →

Often found alongside tundrite-(nd)

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

All properties

Chemical formula: Na₂Nd₂TiO₂(SiO₄)(CO₃)₂
Mohs hardness: 3
Density: 4.02 g/cm³
Colors: Yellow Greenish yellow
Streak: White
Luster: Vitreous
Transparency: Semitransparent
Crystal system: Triclinic
Crystal habit: Tabular crystals, thin plates
Cleavage: Good
Rarity: Rare
Uses: Collector
Host rock: In pegmatite veins associated with layered nepheline syenite

Where rockhounds find tundrite-(nd)

Classic worldwide localities

Ilimaussaq intrusion, at Kringlerne, Kangerdluarssuk Plateau, southern Greenland (type locality)

Field-hunting tip

Where it forms: In pegmatite veins associated with layered nepheline syenite. If you start seeing microcline, arfvedsonite in float, you are in the right ground. Typical habit: tabular crystals, thin plates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tundrite-(nd)?+

Mohs hardness is 3. Luster: vitreous. The streak is white. Common colors include yellow, greenish yellow.

Where is tundrite-(nd) found?+

Notable localities include Ilimaussaq intrusion, at Kringlerne, Kangerdluarssuk Plateau, southern Greenland (type locality).

What rocks look like tundrite-(nd)?+

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

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

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

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

Where it forms: In pegmatite veins associated with layered nepheline syenite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is tundrite-(nd) used for?+

Tundrite-(Nd) is used in collector.

Find tundrite-(nd) on the map

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