Kupčíkite is a very rare copper-iron-germanium sulfide that typically forms as extremely fine, black acicular or hair-like crystals. It is best identified in a laboratory setting through XRD analysis, as it is visually indistinguishable from other similar sulfosalt minerals without detailed testing.
Is this kupčíkite?
4-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 kupčíkite with a known reference. Kupčíkite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: metallic.
- 3Match the color rangeCompare against the expected color range: gray.
- 4Look at form & habitCrystal system: monoclinic. Typical habit: intergrown crystals.
Often confused with
Kupčíkite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside kupčíkite
Minerals reported to co-occur with kupčíkite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₃.₄Fe₀.₆Bi₅S₁₀
- Mohs hardness
- 3.5
- Density
- 5.02 g/cm³
- Colors
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Intergrown crystals
- Rarity
- Rare
- Uses
- Collector
- Host rock
- All rights reserved
Where rockhounds find kupčíkite
Classic worldwide localities
- Felbertal, Austria (type locality)
Field-hunting tip
Where it forms: All rights reserved. If you start seeing quartz, sphalerite, galena in float, you are in the right ground. Typical habit: intergrown crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify kupčíkite?+
Where is kupčíkite found?+
Is kupčíkite safe to handle?+
What rocks look like kupčíkite?+
What minerals are found with kupčíkite?+
What kind of rock does kupčíkite form in?+
What is kupčíkite used for?+
Find kupčíkite on the map
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