Hansblockite is a very rare selenium-bearing mineral typically found as small grains within hydrothermal ore deposits. Collectors primarily find this mineral in advanced mineral suites alongside other rare selenides, often requiring professional analysis for positive identification.

Hardness

3.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareCobaltite Group family

Hansblockite

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

No image

Is this hansblockite?

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 hansblockite with a known reference. Hansblockite 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. Hansblockite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Hansblockite 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: cubic. Typical habit: anhedral grains.

Often confused with

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

mineral

Clausthalite

Mohs 2.5-3

How to tell apart: Streak differs — Hansblockite leaves black, Clausthalite leaves gray-black.

How to tell apart: Hansblockite is noticeably harder (Mohs 3.5 vs. 2.5).

Compare →

Often found alongside hansblockite

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

All properties

Chemical formula: (Bi,Pb)Se₂
Mohs hardness: 3.5
Density: 7.52 g/cm³
Colors: White Gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Anhedral Grains
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $50-300 per specimen

Where rockhounds find hansblockite

Classic worldwide localities

Tarkwa, Ghana
Hope's Nose, Devon, UK

Field-hunting tip

Look in hydrothermal veins country — that is the host setting where hansblockite typically forms. If you start seeing clausthalite, berzelianite, umbertine in float, you are in the right ground. Field specimens usually show a anhedral grains habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hansblockite?+

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

Where is hansblockite found?+

Notable localities include Tarkwa, Ghana; Hope's Nose, Devon, UK.

How much is hansblockite 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 hansblockite safe to handle?+

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

What rocks look like hansblockite?+

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

What minerals are found with hansblockite?+

Hansblockite commonly co-occurs with Clausthalite, Berzelianite, Umbertine. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hansblockite form in?+

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

What is hansblockite used for?+

Hansblockite is used in collector.

Find hansblockite on the map

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