Lautenthalite is a rare secondary mineral typically found as tiny, delicate acicular crystals or radiating groups in lead-copper mining deposits. It is specifically known from the historic mining district of Lautenthal in the Harz Mountains of Germany.

Hardness

2.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareEttringite Group family

Lautenthalite

Hardness: 2.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this lautenthalite?

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 lautenthalite with a known reference. Lautenthalite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Lautenthalite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Lautenthalite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: bright blue.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: acicular crystals, radiating sprays.

Often confused with

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

How to tell apart: Thaumasite is the harder of the two (Mohs 3.5 vs. 2.5).

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Often found alongside lautenthalite

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

All properties

Chemical formula: PbCu₄(SO₄)₂(OH)₆·3H₂O
Mohs hardness: 2.5
Density: 3.84 g/cm³
Colors: Bright Blue
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Acicular Crystals, Radiating Sprays
Cleavage: Perfect On {10-10}
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Ore Veins in Mining Dumps

Where rockhounds find lautenthalite

Classic worldwide localities

Lautenthal, Harz, Germany

Field-hunting tip

Look in hydrothermal ore veins in mining dumps country, the host setting where lautenthalite typically forms. If you start seeing cerussite, brochantite, anglesite in float, you are in the right ground. Field specimens usually show a acicular crystals, radiating sprays habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lautenthalite?+

Mohs hardness is 2.5. It typically shows a vitreous luster. The streak is white. Common colors include bright blue.

Where is lautenthalite found?+

Notable localities include Lautenthal, Harz, Germany.

Is lautenthalite safe to handle?+

It contains toxic constituents. Contains lead and copper; wash hands thoroughly after handling and avoid ingestion or inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like lautenthalite?+

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

What minerals are found with lautenthalite?+

Lautenthalite commonly co-occurs with Cerussite, Brochantite, Anglesite, Linarite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does lautenthalite form in?+

Lautenthalite typically forms in hydrothermal ore veins in mining dumps. Working float back to the host body is the standard way to chase a fresh occurrence.

What is lautenthalite used for?+

Lautenthalite is used in collector.

Find lautenthalite on the map

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