Eskimoite is a rare sulfosalt mineral primarily known from its type locality in the cryolite deposits of Ivigtut, Greenland. It typically occurs as small, needle-like acicular crystals or massive metallic aggregates within hydrothermal environments associated with lead and bismuth sulfides.

Hardness

2.5-3

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareLillianite Group family

Eskimoite

Hardness: 2.5-3
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this eskimoite?

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 eskimoite with a known reference. Eskimoite sits at Mohs 2.5-3 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Eskimoite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Eskimoite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: lead-gray, steel-gray.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: acicular crystals, granular aggregates, massive.

Often confused with

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

mineral

Galena

Mohs 2.5

How to tell apart: Streak differs — Eskimoite leaves black, Galena leaves lead-gray.

How to tell apart: Streak differs — Eskimoite leaves black, Bismuthinite leaves lead-gray.

Often found alongside eskimoite

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

All properties

Chemical formula: Ag₂Pb₃Bi₄S₉
Mohs hardness: 2.5-3
Density: 6.8-7.0 g/cm³
Colors: Lead-gray Steel-gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Acicular Crystals, Granular Aggregates, Massive
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins, Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find eskimoite

Classic worldwide localities

Ivigtut (Ivittuut), Greenland
Bolivia
Czech Republic

Field-hunting tip

Look in hydrothermal veins, pegmatites country — that is the host setting where eskimoite typically forms. If you start seeing galena, siderite, fluorite in float, you are in the right ground. Field specimens usually show a acicular crystals, granular aggregates, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify eskimoite?+

Mohs hardness is 2.5-3. It typically shows a metallic luster. The streak is black. Common colors include lead-gray, steel-gray.

Where is eskimoite found?+

Notable localities include Ivigtut (Ivittuut), Greenland; Bolivia; Czech Republic.

How much is eskimoite 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 eskimoite safe to handle?+

It contains toxic constituents. Contains lead and bismuth; handle with care and avoid inhalation of dust or ingestion. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like eskimoite?+

Eskimoite is most often confused with Galena, Bismuthinite, Lillianite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with eskimoite?+

Eskimoite commonly co-occurs with Galena, Siderite, Fluorite, Cryolite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does eskimoite form in?+

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

What is eskimoite used for?+

Eskimoite is used in collector.

Find eskimoite on the map

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