Edgarite is a very rare sulfide mineral first discovered in the Lovozero Massif of Russia. It appears as metallic, platy crystals that strongly resemble molybdenite in appearance, often occurring in alkaline pegmatite environments.

Hardness

3-3.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Edgarite

Hardness: 3-3.5
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this edgarite?

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

Often confused with

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

mineral

Molybdenite

Mohs 1-1.5

How to tell apart: Edgarite is noticeably harder (Mohs 3-3.5 vs. 1-1.5); streak differs — Edgarite leaves black, Molybdenite leaves greenish-gray.

How to tell apart: Edgarite is noticeably harder (Mohs 3-3.5 vs. 1-2).

Compare →

Often found alongside edgarite

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

All properties

Chemical formula: FeNb₃S₆
Mohs hardness: 3-3.5
Density: 4.67 g/cm³
Colors: Black Gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Trigonal
Crystal habit: Platy, Foliated, Massive
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector
Host rock: Alkaline Pegmatites
Typical price: $100-500 for small specimens

Where rockhounds find edgarite

Classic worldwide localities

Lovozero Massif, Russia

Field-hunting tip

Look in alkaline pegmatites country — that is the host setting where edgarite typically forms. If you start seeing molybdenite, eudialyte, nepheline in float, you are in the right ground. Field specimens usually show a platy, foliated, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify edgarite?+

Mohs hardness is 3-3.5. It typically shows a metallic luster. The streak is black. Common colors include black, gray.

Where is edgarite found?+

Notable localities include Lovozero Massif, Russia.

How much is edgarite worth?+

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

What rocks look like edgarite?+

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

What minerals are found with edgarite?+

Edgarite commonly co-occurs with Molybdenite, Eudialyte, Nepheline, Microcline. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does edgarite form in?+

Edgarite typically forms in alkaline pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is edgarite used for?+

Edgarite is used in collector.

Find edgarite on the map

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