Paracoquimbite is a rare hydrated iron sulfate that forms in the oxidized zones of pyrite-rich ore deposits in arid climates. It is frequently found as a dimorph of Coquimbite, often forming pale violet to white hexagonal plates or granular crusts. Due to its high solubility in water, specimens must be stored in a dry, airtight environment to prevent dehydration and breakdown.
Is this paracoquimbite?
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 paracoquimbite with a known reference. Paracoquimbite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: light violet.
- 5Look at form & habitCrystal system: trigonal. Typical habit: hexagonal plates, pseudo-hexagonal crystals, granular masses.
Often confused with
Paracoquimbite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside paracoquimbite
Minerals reported to co-occur with paracoquimbite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe₂(SO₄)₃·9H₂O
- Mohs hardness
- 2.5
- Density
- 2.11 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Hexagonal plates, pseudo-hexagonal crystals, granular masses
- Cleavage
- On {0112} and {1014}, imperfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare mineral formed in the oxidized zone of pyritic hydrothermal orebodies, especially in arid regions
Where rockhounds find paracoquimbite
Classic worldwide localities
- Steamboat Springs, Washoe Co., Nevada, USA
- Tierra Amarilla, southeast of Copiapó, Atacama, Chile
- Chuquicamata, Alcaparrosa, near Cerritos Bayos, southwest of Calama, and Quetena, west of Calama, Antofagasta, Chile
- Myoban Spa, Oita Prefecture, Japan
- Kamariza mine, Laurium, Greece
Field-hunting tip
Where it forms: A rare mineral formed in the oxidized zone of pyritic hydrothermal orebodies, especially in arid regions. If you start seeing coquimbite, römerite, szomolnokite in float, you are in the right ground. Typical habit: hexagonal plates, pseudo-hexagonal crystals, granular masses. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify paracoquimbite?+
Where is paracoquimbite found?+
What rocks look like paracoquimbite?+
What minerals are found with paracoquimbite?+
What kind of rock does paracoquimbite form in?+
What is paracoquimbite used for?+
Find paracoquimbite on the map
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