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.
Is this edgarite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch edgarite with a known reference. Edgarite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: black, dark gray.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: platy.
Often confused with
Edgarite vs. its common look-alikes, and how to tell them apart in the field.
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
- 2-2.5
- Density
- 4.98 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Hexagonal
- Crystal habit
- Platy
- Cleavage
- Perfect on {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a feldspar-rich fenitized xenolith in a differentiated alkalic massif
Where rockhounds find edgarite
Classic worldwide localities
- Khibiny massif, Kola Peninsula, Russia (type locality)
Field-hunting tip
Where it forms: In a feldspar-rich fenitized xenolith in a differentiated alkalic massif. If you start seeing ti-v-rich pyrrhotite, ti-v-rich marcasite, alabandite in float, you are in the right ground. Typical habit: platy. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify edgarite?+
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What rocks look like edgarite?+
What minerals are found with edgarite?+
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Find edgarite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
