Viaeneite is a rare iron-lead sulfide-oxide mineral that occurs as black, microcrystalline crusts. It was discovered in the Engis zinc-lead deposit in Belgium, typically forming in association with other sulfide minerals in limestone.

Hardness

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Viaeneite

Hardness: 3
Luster: Metallic
Streak: Black
Transparency: Opaque

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Is this viaeneite?

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 viaeneite with a known reference. Viaeneite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: black.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic.
4
Match the color range
Compare against the expected color range: yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: aggregates, spherical.

Often confused with

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

mineral

Pyrite

Mohs 6-6.5

How to tell apart: Pyrite is the harder of the two (Mohs 6-6.5 vs. 3); streak differs, so Viaeneite leaves black, Pyrite leaves greenish black to brownish black.

How to tell apart: Marcasite is the harder of the two (Mohs 6-6.5 vs. 3); streak differs, so Viaeneite leaves black, Marcasite leaves grayish or brownish black.

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Often found alongside viaeneite

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

All properties

Chemical formula: (Fe,Pb)₄S₈O
Mohs hardness: 3
Density: 3.8 g/cm³
Colors: Yellow
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Aggregates, spherical
Cleavage: On {110}, clearly observed under transmission electron microscopy
Rarity: Rare
Uses: Collector
Host rock: In a carbonate-hosted Pb–Zn deposit

Where rockhounds find viaeneite

Classic worldwide localities

Mallieue Pb–Zn deposit, Engis, about 40 km southwest of Liège, Belgium (type locality)

Field-hunting tip

Where it forms: In a carbonate-hosted Pb–Zn deposit. If you start seeing pyrite, melnikovite, marcasite in float, you are in the right ground. Typical habit: aggregates, spherical. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify viaeneite?+

Mohs hardness is 3. Luster: metallic. The streak is black. Common colors include yellow.

Where is viaeneite found?+

Notable localities include Mallieue Pb–Zn deposit, Engis, about 40 km southwest of Liège, Belgium (type locality).

Is viaeneite safe to handle?+

Viaeneite contains lead. Contains lead and iron sulfides; avoid ingestion, inhalation of dust, or prolonged skin contact.

What rocks look like viaeneite?+

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

What minerals are found with viaeneite?+

Viaeneite commonly co-occurs with Pyrite, Melnikovite, Marcasite, Greigite, Sphalerite, Galena. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does viaeneite form in?+

Where it forms: In a carbonate-hosted Pb–Zn deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is viaeneite used for?+

Viaeneite is used in collector.

Find viaeneite on the map

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