Mooihoekite is a rare copper-iron sulfide mineral found primarily in layered ultramafic complexes. It is visually very similar to chalcopyrite, often occurring as intergrowths, and typically requires laboratory analysis for definitive identification.
Is this mooihoekite?
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 mooihoekite with a known reference. Mooihoekite sits at Mohs 4, 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: brass yellow, dark purple, pink brown.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: granular.
Often confused with
Mooihoekite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside mooihoekite
Minerals reported to co-occur with mooihoekite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₉Fe₉S₁₆
- Mohs hardness
- 4
- Density
- 4.36 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Granular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In massive sulfide from a pipe-shaped dunite pegmatite in the Norite Zone of the Bushveld complex (Mooihoek mine, South Africa); in troctolite from the basal Duluth Gabbro complex (Minnesota, USA)
Where rockhounds find mooihoekite
Classic worldwide localities
- Duluth Gabbro complex, near Hibbing, St. Louis Co., Minnesota, USA
- Transvaal, in the Mooihoek mine, Lydenburg district (type locality), and from the Townlands pipe, Rustenburg, South Africa
- Talnakh area, Noril’sk region, western Siberia, Russia
- Krzemianka, Poland
- Malanjkhand Cu–Mo deposit, Madhya-Pradesh, India
Field-hunting tip
Where it forms: In massive sulfide from a pipe-shaped dunite pegmatite in the Norite Zone of the Bushveld complex (Mooihoek mine, South Africa); in troctolite from the basal Duluth Gabbro complex (Minnesota, USA). If you start seeing haycockite, magnetite, troilite in float, you are in the right ground. Typical habit: granular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify mooihoekite?+
Where is mooihoekite found?+
Is mooihoekite safe to handle?+
What rocks look like mooihoekite?+
What minerals are found with mooihoekite?+
What kind of rock does mooihoekite form in?+
What is mooihoekite used for?+
Find mooihoekite on the map
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