Kenngottite is a rare silver arsenic sulfosalt often found as an accessory in complex hydrothermal vein systems. It is virtually indistinguishable from members of the polybasite-pearceite series without sophisticated chemical analysis like X-ray diffraction or EDS. Collectors look for its dark metallic, opaque appearance typically associated with other silver-bearing minerals.

Hardness

2-3

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrarePolybasite Group family

Kenngottite

Hardness: 2-3
Luster: Metallic
Streak: Black
Transparency: Opaque

No image

Is this kenngottite?

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

Often confused with

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

Often found alongside kenngottite

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

All properties

Chemical formula: (Ag,Cu)₁₆As₂S₁₁
Mohs hardness: 2-3
Density: 6.4-6.5 g/cm³
Colors: Iron-black Dark Gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Tabular Crystals, Massive, Granular
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $50-500 thumbnail depending on locality

Where rockhounds find kenngottite

Classic worldwide localities

Radusa, North Macedonia
Guanajuato, Mexico
Freiberg, Germany

Field-hunting tip

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

Common questions

How do you identify kenngottite?+

Mohs hardness is 2-3. It typically shows a metallic luster. The streak is black. Common colors include iron-black, dark gray.

Where is kenngottite found?+

Notable localities include Radusa, North Macedonia; Guanajuato, Mexico; Freiberg, Germany.

How much is kenngottite worth?+

Typical asking prices fall in the range of $50-500 thumbnail depending on locality. Quality, size, and provenance can move individual specimens well outside that range.

Is kenngottite safe to handle?+

It contains toxic constituents. Contains arsenic and silver; handle with care, wash hands thoroughly after handling, and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like kenngottite?+

Kenngottite is most often confused with Polybasite, Pearceite, Stephanite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with kenngottite?+

Kenngottite commonly co-occurs with Arsenopyrite, Pyrite, Sphalerite, Calcite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kenngottite form in?+

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

What is kenngottite used for?+

Kenngottite is used in collector.

Find kenngottite on the map

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