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 — that is 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.