Calcjarlite is a rare fluoride mineral discovered primarily in the cryolite deposits of Greenland. It typically occurs in granular masses or small tabular crystals and is prized by advanced systematic mineral collectors.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Calcjarlite

Hardness: ~4
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this calcjarlite?

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 calcjarlite with a known reference. Calcjarlite 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. 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: white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals, massive, granular.

Often confused with

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

mineral

Cryolite

Mohs 2.5

How to tell apart: Calcjarlite is noticeably harder (Mohs ~4 vs. 2.5).

Often found alongside calcjarlite

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

All properties

Chemical formula: Na₂(Ca,□)₁₄(Mg,□)₂Al₁₂F₆₄(OH)₄
Mohs hardness: ~4
Density: 3.51 g/cm³
Colors: White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular crystals, massive, granular
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In a fluorite vein in quartz-mica schists

Where rockhounds find calcjarlite

Classic worldwide localities

Mouth of the second tributary to the Pravaya Noyba River, tributary to the Teya River, Yenisei Ridge, Siberia, Russia

Field-hunting tip

Where it forms: In a fluorite vein in quartz-mica schists. If you start seeing fluorite, thorite, usovite in float, you are in the right ground. Typical habit: tabular crystals, massive, granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify calcjarlite?+

Mohs hardness is ~4. Luster: vitreous. The streak is white. Common colors include white.

Where is calcjarlite found?+

Notable localities include Mouth of the second tributary to the Pravaya Noyba River, tributary to the Teya River, Yenisei Ridge, Siberia, Russia.

What rocks look like calcjarlite?+

Calcjarlite is most often confused with Cryolite, Jarlite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with calcjarlite?+

Calcjarlite commonly co-occurs with Fluorite, Thorite, Usovite, Chamosite, Phillipsite, Erionite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does calcjarlite form in?+

Where it forms: In a fluorite vein in quartz-mica schists. Working float back to the host body is the standard way to chase a fresh occurrence.

What is calcjarlite used for?+

Calcjarlite is used in collector.

Find calcjarlite on the map

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