Langbeinite is a rare potassium magnesium sulfate mineral found primarily in marine evaporite deposits. It typically forms as tetrahedral crystals or massive granular aggregates and is highly valued as a source of potash for high-quality fertilizers.

Hardness

3.5-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineraluncommon

Langbeinite

Hardness: 3.5-4
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this langbeinite?

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 langbeinite with a known reference. Langbeinite sits at Mohs 3.5-4, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Langbeinite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Langbeinite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white, gray, yellowish, pinkish.
5
Look at form & habit
Crystal system: isometric. Typical habit: tetrahedral crystals, massive, granular.

Often confused with

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

mineral

Halite

Mohs 2.5

How to tell apart: Langbeinite is noticeably harder (Mohs 3.5-4 vs. 2.5).

How to tell apart: Langbeinite is noticeably harder (Mohs 3.5-4 vs. 2).

Compare →

Often found alongside langbeinite

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

All properties

Chemical formula: K₂Mg₂(SO₄)₃
Mohs hardness: 3.5-4
Density: 2.83 g/cm³
Colors: Colorless White Gray Yellowish Pinkish
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Isometric
Crystal habit: Tetrahedral Crystals, Massive, Granular
Cleavage: None
Rarity: Uncommon
Uses: Collector, Fertilizer, Industrial
Host rock: Marine Evaporite Deposits
Typical price: $10-60 for small mineral specimens

Where rockhounds find langbeinite

Classic worldwide localities

Stassfurt, Germany
Carlsbad, New Mexico, USA
Kalush, Ukraine
Hallsberg, Sweden

Field-hunting tip

Look in marine evaporite deposits country, the host setting where langbeinite typically forms. If you start seeing halite, sylvite, kainite in float, you are in the right ground. Field specimens usually show a tetrahedral crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify langbeinite?+

Mohs hardness is 3.5-4. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, gray, yellowish.

Where is langbeinite found?+

Notable localities include Stassfurt, Germany; Carlsbad, New Mexico, USA; Kalush, Ukraine; Hallsberg, Sweden.

How much is langbeinite worth?+

Typical asking prices fall in the range of $10-60 for small mineral specimens. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like langbeinite?+

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

What minerals are found with langbeinite?+

Langbeinite commonly co-occurs with Halite, Sylvite, Kainite, Anhydrite, Carnallite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does langbeinite form in?+

Langbeinite typically forms in marine evaporite deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is langbeinite used for?+

Langbeinite is used in collector, fertilizer, industrial.

Find langbeinite on the map

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