Cerromojonite is an extremely rare lead tungsten sulfide mineral found in high-sulfidation hydrothermal deposits. It typically occurs as small, dark grey granular aggregates associated with galena and other sulfide minerals in its type locality in Bolivia.

Hardness

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrarenull family

Cerromojonite

Hardness: 2
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this cerromojonite?

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 cerromojonite with a known reference. Cerromojonite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Cerromojonite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Cerromojonite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: dark gray, lead gray.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: granular to massive.

Often confused with

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

mineral

Galena

Mohs 2.5

How to tell apart: Streak differs — Cerromojonite leaves black, Galena leaves lead-gray.

How to tell apart: Streak differs — Cerromojonite leaves black, Bournonite leaves steel-gray.

Compare →

Often found alongside cerromojonite

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

All properties

Chemical formula: Pb₆W₂O₉S₂
Mohs hardness: 2
Density: 6.8 g/cm³
Colors: Dark Gray Lead Gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Granular to Massive
Cleavage: None Observed
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Tin-silver Veins
Typical price: $100-500 thumbnail

Where rockhounds find cerromojonite

Classic worldwide localities

Cerro Mojón, Potosí, Bolivia

Field-hunting tip

Look in hydrothermal tin-silver veins country — that is the host setting where cerromojonite typically forms. If you start seeing galena, sphalerite, pyrite in float, you are in the right ground. Field specimens usually show a granular to massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify cerromojonite?+

Mohs hardness is 2. It typically shows a metallic luster. The streak is black. Common colors include dark gray, lead gray.

Where is cerromojonite found?+

Notable localities include Cerro Mojón, Potosí, Bolivia.

How much is cerromojonite worth?+

Typical asking prices fall in the range of $100-500 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

Is cerromojonite safe to handle?+

It contains toxic constituents. Contains lead, which is a toxic heavy metal. Handle with care, wash hands after touching, and avoid inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like cerromojonite?+

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

What minerals are found with cerromojonite?+

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

What kind of rock does cerromojonite form in?+

Cerromojonite typically forms in hydrothermal tin-silver veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is cerromojonite used for?+

Cerromojonite is used in collector.

Find cerromojonite on the map

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