Naujakasite is a rare phyllosilicate mineral primarily found in the complex igneous rocks of Greenland's Ilimaussaq complex. It is characterized by its silvery-white, pearly, platy appearance that strongly resembles mica, often occurring as lamellar masses within pegmatitic dikes.

Hardness

2-3

Mohs

Luster

Pearly on {001}

Streak

Gray white

Transparency

Semitransparent

mineralrare

Naujakasite

Hardness: 2-3
Luster: Pearly on {001}
Streak: Gray white
Transparency: Semitransparent

Is this naujakasite?

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 naujakasite with a known reference. Naujakasite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: gray white.
3
Read the luster
Hold the specimen under a strong light. Luster: pearly on {001}.
4
Match the color range
Compare against the expected color range: gray, pearl white, silver white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: aggregates, micaceous, platy.

Often confused with

Naujakasite vs. its common look-alikes, and how to tell them apart in the field.

mineral

Leifite

Mohs 6

How to tell apart: Leifite is the harder of the two (Mohs 6 vs. 2-3); streak differs, so Naujakasite leaves gray white, Leifite leaves white; luster reads pearly on {001} on Naujakasite and silky on Leifite.

Compare →

Often found alongside naujakasite

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

All properties

Chemical formula: Na₆FeAl₄Si₈O₂₆
Mohs hardness: 2-3
Density: 2.615-2.622 g/cm³
Colors: Gray Pearl white Silver white
Streak: Gray white
Luster: Pearly on {001}
Transparency: Semitransparent
Crystal system: Monoclinic
Crystal habit: Aggregates, micaceous, platy
Cleavage: Perfect micaceous on {001}; {401} and {010}, distinct
Rarity: Rare
Uses: Collector
Host rock: In an alkalic intrusion

Where rockhounds find naujakasite

Classic worldwide localities

Naujakasik, Tunugdliarfik Fjord, Greenland (type locality)

Field-hunting tip

Where it forms: In an alkalic intrusion. If you start seeing arfvedsonite, sodalite, steenstrupine in float, you are in the right ground. Typical habit: aggregates, micaceous, platy. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify naujakasite?+

Mohs hardness is 2-3. Luster: pearly on {001}. The streak is gray white. Common colors include gray, pearl white, silver white.

Where is naujakasite found?+

Notable localities include Naujakasik, Tunugdliarfik Fjord, Greenland (type locality).

What rocks look like naujakasite?+

Naujakasite is most often confused with Leifite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with naujakasite?+

Naujakasite commonly co-occurs with Arfvedsonite, Sodalite, Steenstrupine, Analcime. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does naujakasite form in?+

Where it forms: In an alkalic intrusion. Working float back to the host body is the standard way to chase a fresh occurrence.

What is naujakasite used for?+

Naujakasite is used in collector.

Find naujakasite on the map

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