Lahnsteinite is a rare secondary zinc sulfate mineral typically found as delicate, pearly-white coatings or small platy crystals in oxidized mine environments. It is named after its type locality in Lahnstein, Germany, and is highly sought after by collectors of micro-minerals and rare species.

Hardness

Mohs

Transparency

Translucent

mineralrare

Lahnsteinite

Hardness: 1.5
Transparency: Translucent

No image

Is this lahnsteinite?

3-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 lahnsteinite with a known reference. Lahnsteinite sits at Mohs 1.5, softer than the next harder reference, harder than the previous one.
2
Match the color range
Compare against the expected color range: colorless.
3
Look at form & habit
Crystal system: triclinic. Typical habit: platy crystals, crusts.

Often confused with

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

mineral

Gordaite

Mohs 2.5

How to tell apart: Gordaite is the harder of the two (Mohs 2.5 vs. 1.5).

Often found alongside lahnsteinite

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

All properties

Chemical formula: Zn₄(SO₄)(OH)₆·3H₂O
Mohs hardness: 1.5
Density: 2.98 g/cm³
Colors: Colorless
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Platy crystals, crusts
Cleavage: Perfect on {001}, 2 more less-perfect sets perpendicular to (001)
Rarity: Rare
Uses: Collector
Host rock: In the oxidized zone of a hydrothermal polymetallic sulfide deposit

Where rockhounds find lahnsteinite

Classic worldwide localities

Lahnstein, Rhineland-Palatinate, Germany

Field-hunting tip

Where it forms: In the oxidized zone of a hydrothermal polymetallic sulfide deposit. If you start seeing hydrozincite, pyromorphite, native copper in float, you are in the right ground. Typical habit: platy crystals, crusts. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lahnsteinite?+

Mohs hardness is 1.5. Common colors include colorless.

Where is lahnsteinite found?+

Notable localities include Lahnstein, Rhineland-Palatinate, Germany.

Is lahnsteinite safe to handle?+

Contains zinc, which can be toxic if ingested or inhaled as dust. Wash hands thoroughly after handling specimens.

What rocks look like lahnsteinite?+

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

What minerals are found with lahnsteinite?+

Lahnsteinite commonly co-occurs with Hydrozincite, Pyromorphite, Native copper, Goethite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does lahnsteinite form in?+

Where it forms: In the oxidized zone of a hydrothermal polymetallic sulfide deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is lahnsteinite used for?+

Lahnsteinite is used in collector.

Find lahnsteinite on the map

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