Naumannite is a rare silver selenide mineral typically found in low-temperature hydrothermal veins. It is distinguished by its heavy feel, metallic lead-gray color, and characteristic association with other rare selenides and precious metals.

Hardness

2.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineraluncommon

Naumannite

Hardness: 2.5
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this naumannite?

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 naumannite with a known reference. Naumannite 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. 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: grayish black, iron black.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: massive.

Often confused with

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

How to tell apart: Streak differs, so Naumannite leaves black, Galena leaves lead-gray.

Compare →

Often found alongside naumannite

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

All properties

Chemical formula: Ag₂Se
Mohs hardness: 2.5
Density: 7.0-8.0 g/cm³
Colors: Grayish black Iron black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Massive
Cleavage: Perfect
Rarity: Uncommon
Uses: Collector, Ore of silver
Host rock: In hydrothermal veins deficient in sulfur, associated with other selenides, quartz, and carbonates

Where rockhounds find naumannite

Classic worldwide localities

Republic, Ferry Co., and in the L-D mine, Wenatchee, Chelan Co., Washington, USA
De Lamar mine, Silver City district, Owyhee Co., and from the 4th of July mine, Yankee Fork, Custer Co., Idaho, USA
Ken Snyder mine, Gold Circle district, Elko Co., and at the Rex Grande deposit, Midas, Elko Co., Nevada, USA
Harz Mountains, at Tilkerode (type locality) and St. Andreasberg, Germany
Săcărı̂mb (Nagyág), Romania
Předbořice deposit, Czech Republic

Field-hunting tip

Where it forms: In hydrothermal veins deficient in sulfur, associated with other selenides, quartz, and carbonates. If you start seeing clausthalite, aguilarite, acanthite in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify naumannite?+

Mohs hardness is 2.5. Luster: metallic. The streak is black. Common colors include grayish black, iron black.

Where is naumannite found?+

Notable localities include Republic, Ferry Co., and in the L-D mine, Wenatchee, Chelan Co., Washington, USA; De Lamar mine, Silver City district, Owyhee Co., and from the 4th of July mine, Yankee Fork, Custer Co., Idaho, USA; Ken Snyder mine, Gold Circle district, Elko Co., and at the Rex Grande deposit, Midas, Elko Co., Nevada, USA; Harz Mountains, at Tilkerode (type locality) and St. Andreasberg, Germany; Săcărı̂mb (Nagyág), Romania.

Is naumannite safe to handle?+

Naumannite contains selenium. Contains silver and selenium; dust and fumes are toxic if inhaled or ingested. Wash hands thoroughly after handling and avoid creating dust when prepping specimens.

What rocks look like naumannite?+

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

What minerals are found with naumannite?+

Naumannite commonly co-occurs with Clausthalite, Aguilarite, Acanthite, Tiemannite, Umangite, Eucairite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does naumannite form in?+

Where it forms: In hydrothermal veins deficient in sulfur, associated with other selenides, quartz, and carbonates. Working float back to the host body is the standard way to chase a fresh occurrence.

What is naumannite used for?+

Naumannite is used in collector, ore of silver.

Find naumannite on the map

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