Eugenite is a rare silver-mercury alloy belonging to the amalgam group. It typically occurs as small, silver-white grains or masses within hydrothermal veins and is a significant mercury-bearing mineral for specialized collectors.

Hardness

Mohs

Luster

Metallic

Streak

Silver-white

Transparency

Opaque

mineralrareAmalgam Group family

Eugenite

Hardness: 3
Luster: Metallic
Streak: Silver-white
Transparency: Opaque

Is this eugenite?

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 eugenite with a known reference. Eugenite 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. Eugenite leaves a silver-white streak.
3
Read the luster
Hold the specimen under a strong light. Eugenite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: silver-white.
5
Look at form & habit
Crystal system: cubic. Typical habit: grains, small masses.

Often confused with

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

How to tell apart: Streak differs — Eugenite leaves silver-white, Dyscrasite leaves black.

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Often found alongside eugenite

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

All properties

Chemical formula: Ag₁₁Hg₂
Mohs hardness: 3
Density: 11.1 g/cm³
Colors: Silver-white
Streak: Silver-white
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Grains, Small Masses
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Silver-mercury Veins
Typical price: $100-500 for small samples

Where rockhounds find eugenite

Classic worldwide localities

Freiberg, Saxony, Germany
Kongsberg, Norway
Terlingua, Texas, USA

Field-hunting tip

Look in hydrothermal silver-mercury veins country — that is the host setting where eugenite typically forms. If you start seeing silver, cinnabar, calcite in float, you are in the right ground. Field specimens usually show a grains, small masses habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify eugenite?+

Mohs hardness is 3. It typically shows a metallic luster. The streak is silver-white. Common colors include silver-white.

Where is eugenite found?+

Notable localities include Freiberg, Saxony, Germany; Kongsberg, Norway; Terlingua, Texas, USA.

How much is eugenite worth?+

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

Is eugenite safe to handle?+

It contains toxic constituents. Contains mercury; handle with care, avoid inhalation of dust, wash hands after handling, and store in a sealed container. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like eugenite?+

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

What minerals are found with eugenite?+

Eugenite commonly co-occurs with Silver, Cinnabar, Calcite, Dolomite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does eugenite form in?+

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

What is eugenite used for?+

Eugenite is used in collector.

Find eugenite on the map

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