Belendorffite is a rare copper-mercury amalgam found in oxidized zones of mercury deposits. It typically occurs as minute, silver-white metallic grains or small aggregates associated with native mercury and cinnabar.

Hardness

2.5-4

Mohs

Luster

Metallic

Streak

Silvery

Transparency

Opaque

mineralrareAmalgam family

Belendorffite

Hardness: 2.5-4
Luster: Metallic
Streak: Silvery
Transparency: Opaque

Is this belendorffite?

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 belendorffite with a known reference. Belendorffite sits at Mohs 2.5-4, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: silvery.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic.
4
Match the color range
Compare against the expected color range: white, yellow, blackish brown.
5
Look at form & habit
Crystal system: trigonal. Typical habit: irregular grains, small masses.

Often confused with

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

mineral

Potarite

Mohs 3.5

How to tell apart: Streak differs, so Belendorffite leaves silvery, Potarite leaves silver-white.

How to tell apart: Belendorffite is noticeably harder (Mohs 2.5-4 vs. 0).

Compare →

Often found alongside belendorffite

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

Mercury
mineral · Mohs 0

All properties

Chemical formula: Cu₇Hg₆
Mohs hardness: 2.5-4
Density: 13.2 g/cm³
Colors: White Yellow Blackish brown
Streak: Silvery
Luster: Metallic
Transparency: Opaque
Crystal system: Trigonal
Crystal habit: Irregular grains, small masses
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In a mercury deposit

Where rockhounds find belendorffite

Classic worldwide localities

Landsberg, near Obermoschel, Rhineland-Palatinate, Germany (type locality)

Field-hunting tip

Where it forms: In a mercury deposit. If you start seeing mercury in float, you are in the right ground. Typical habit: irregular grains, small masses. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify belendorffite?+

Mohs hardness is 2.5-4. Luster: metallic. The streak is silvery. Common colors include white, yellow, blackish brown.

Where is belendorffite found?+

Notable localities include Landsberg, near Obermoschel, Rhineland-Palatinate, Germany (type locality).

Is belendorffite safe to handle?+

Belendorffite contains copper and mercury and calls for real care. Contains mercury; handle with caution, avoid ingestion, inhalation of dust, or skin contact. Wash hands thoroughly after handling.

What rocks look like belendorffite?+

Belendorffite is most often confused with Potarite, Native Mercury. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with belendorffite?+

Belendorffite commonly co-occurs with Mercury. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does belendorffite form in?+

Where it forms: In a mercury deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is belendorffite used for?+

Belendorffite is used in collector.

Find belendorffite on the map

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