Ekplexite is a rare copper-niobium sulfide mineral found primarily in alkaline igneous environments. It typically occurs as small, dark, metallic platy crystals that resemble molybdenite but are distinguished by their specific composition and geological context in the Kola Peninsula.
Is this ekplexite?
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 ekplexite with a known reference. Ekplexite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Ekplexite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Ekplexite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: black, dark gray.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy or micaceous aggregates.
Often confused with
Ekplexite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside ekplexite
Minerals reported to co-occur with ekplexite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Cu,Fe)₄Nb₂S₇
- Mohs hardness
- 2
- Density
- 5.65 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Platy or Micaceous Aggregates
- Cleavage
- Perfect Basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Pegmatites
- Typical price
- $50-300 per specimen
Where rockhounds find ekplexite
Classic worldwide localities
- Khibiny Massif, Russia
- Lovozero Massif, Russia
Field-hunting tip
Look in alkaline pegmatites country — that is the host setting where ekplexite typically forms. If you start seeing aegirine, nepheline, microcline in float, you are in the right ground. Field specimens usually show a platy or micaceous aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ekplexite?+
Where is ekplexite found?+
How much is ekplexite worth?+
What rocks look like ekplexite?+
What minerals are found with ekplexite?+
What kind of rock does ekplexite form in?+
What is ekplexite used for?+
Find ekplexite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
