Polhemusite is an extremely rare zinc-mercury sulfide mineral typically found in low-temperature hydrothermal deposits. It is best identified by its association with mercury minerals and its characteristic occurrence as minute, metallic, tetragonal tabular crystals.

Hardness

3.5

Mohs

Luster

Metallic

Streak

White

Transparency

Opaque

mineralrare

Polhemusite

Hardness: 3.5
Luster: Metallic
Streak: White
Transparency: Opaque

Is this polhemusite?

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 polhemusite with a known reference. Polhemusite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Polhemusite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Polhemusite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: white, gray.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: tabular crystals, massive.

Often confused with

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

mineral

Sphalerite

Mohs 3.5-4

How to tell apart: Streak differs, so Polhemusite leaves white, Sphalerite leaves white to yellow-brown; luster reads metallic on Polhemusite and resinous to submetallic on Sphalerite.

How to tell apart: Polhemusite is noticeably harder (Mohs 3.5 vs. 2-2.5); streak differs, so Polhemusite leaves white, Cinnabar leaves scarlet; luster reads metallic on Polhemusite and adamantine on Cinnabar.

Compare →

Often found alongside polhemusite

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

All properties

Chemical formula: (Zn,Hg)S
Mohs hardness: 3.5
Density: 4.96 g/cm³
Colors: White Gray
Streak: White
Luster: Metallic
Transparency: Opaque
Crystal system: Tetragonal
Crystal habit: Tabular Crystals, Massive
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $50-300 per specimen

Where rockhounds find polhemusite

Classic worldwide localities

Mercur District, Utah, USA

Field-hunting tip

Look in hydrothermal veins country, the host setting where polhemusite typically forms. If you start seeing cinnabar, realgar, calcite in float, you are in the right ground. Field specimens usually show a tabular crystals, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify polhemusite?+

Mohs hardness is 3.5. It typically shows a metallic luster. The streak is white. Common colors include white, gray.

Where is polhemusite found?+

Notable localities include Mercur District, Utah, USA.

How much is polhemusite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is polhemusite safe to handle?+

It contains toxic constituents. Contains mercury; handle with caution, avoid ingestion or inhalation of dust, and wash hands thoroughly after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like polhemusite?+

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

What minerals are found with polhemusite?+

Polhemusite commonly co-occurs with Cinnabar, Realgar, Calcite, Pyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does polhemusite form in?+

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

What is polhemusite used for?+

Polhemusite is used in collector.

Find polhemusite on the map

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