Rheniite is a exceptionally rare rhenium sulfide mineral that primarily occurs in high-temperature volcanic fumaroles. It typically forms thin, metallic, platy crystals that closely resemble molybdenite, but it is unique for being the only mineral where rhenium is an essential constituent. Most specimens are sourced from the Kudryavy Volcano in the Kuril Islands, where it was first discovered.
Is this rheniite?
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 rheniite with a known reference. Rheniite sits at Mohs 1.5-2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: gray-black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: silver gray.
- 5Look at form & habitCrystal system: triclinic. Typical habit: platy.
Often confused with
Rheniite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside rheniite
Minerals reported to co-occur with rheniite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- ReS₂
- Mohs hardness
- 1.5-2
- Density
- 7.598 g/cm³
- Colors
- Streak
- Gray-black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Triclinic
- Crystal habit
- Platy
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector, Research
- Host rock
- As sublimates in high-temperature fumaroles and in porphyry-type Mo-Cu-Te-Ag-Au hydrothermal mineralization
Where rockhounds find rheniite
Classic worldwide localities
- Kudryavy volcano, Kurile volcanic arc, Russia (type locality) and in the Pagoni Rachi and Konos prospects, in northeastern Greece
Field-hunting tip
Where it forms: As sublimates in high-temperature fumaroles and in porphyry-type Mo-Cu-Te-Ag-Au hydrothermal mineralization. If you start seeing molybdenite, pyrite, quartz 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 rheniite?+
Where is rheniite found?+
What rocks look like rheniite?+
What minerals are found with rheniite?+
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What is rheniite used for?+
Find rheniite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
