Huenite is a rare copper molybdate, typically dark reddish-brown. Associated minerals include lindgrenite, gypsum and tourmaline. It was first described from the San Samuel Mine, Copiapó Province, Atacama Region, Chile.
Is this huenite?
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 huenite with a known reference. Huenite sits at Mohs 3.5-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale reddish brown to pinkish.
- 3Read the lusterHold the specimen under a strong light. Luster: strong vitreous to adamantine.
- 4Match the color rangeCompare against the expected color range: dark reddish-brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy crystals, crusts.
Often confused with
Huenite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Emmonsite is the harder of the two (Mohs ~5 vs. 3.5-4); luster reads strong vitreous to adamantine on Huenite and vitreous on Emmonsite.
How to tell apart: Huenite is noticeably harder (Mohs 3.5-4 vs. 2); streak differs, so Huenite leaves pale reddish brown to pinkish, Tellurite leaves white; luster reads strong vitreous to adamantine on Huenite and subadamantine on Tellurite.
Often found alongside huenite
Minerals reported to co-occur with huenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₄(MoO₄)₃(OH)₂
- Mohs hardness
- 3.5-4
- Density
- 5.1 g/cm³
- Colors
- Streak
- Pale reddish brown to pinkish
- Luster
- Strong vitreous to adamantine
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Platy crystals, crusts
- Cleavage
- Good on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- An oxidation product of primary sulfides formed by late-stage hydrothermal fluids as open-space fillings in pipes of tourmalinized quartz porphyry, collapse-breccia
Where rockhounds find huenite
Classic worldwide localities
- San Samuel Mine, Carrera Pinto, Cachiyuyo de Llampos district, Copiapó Province, Atacama Region, Chile
Field-hunting tip
Where it forms: An oxidation product of primary sulfides formed by late-stage hydrothermal fluids as open-space fillings in pipes of tourmalinized quartz porphyry, collapse-breccia. If you start seeing lindgrenite, gypsum, tourmaline in float, you are in the right ground. Typical habit: platy crystals, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
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Find huenite on the map
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