Parabutlerite is a rare secondary iron sulfate mineral typically formed through the oxidation of pyrite in arid environments. It appears as delicate orange or yellow platy crystals or crusts, often found in association with other rare sulfates in volcanic or desert mining districts.
Is this parabutlerite?
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 parabutlerite with a known reference. Parabutlerite 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: light yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: light brown orange, light orange, orange brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic, striated.
Often confused with
Parabutlerite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Parabutlerite leaves light yellow, Butlerite leaves pale yellow.
How to tell apart: Streak differs, so Parabutlerite leaves light yellow, Copiapite leaves pale yellow; luster reads vitreous on Parabutlerite and pearly on {010} on Copiapite.
How to tell apart: Streak differs, so Parabutlerite leaves light yellow, Fibroferrite leaves white; luster reads vitreous on Parabutlerite and pearly, silky in aggregates on Fibroferrite.
Often found alongside parabutlerite
Minerals reported to co-occur with parabutlerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe³⁺(SO₄)(OH)·2H₂O
- Mohs hardness
- 2.5
- Density
- 2.55 g/cm³
- Colors
- Streak
- Light yellow
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic, striated
- Cleavage
- Poor on {110}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- An uncommon mineral in the oxidized zone of pyritic veins, may be formed by alteration of other sulfates
Where rockhounds find parabutlerite
Classic worldwide localities
- Dexter No. 7 mine, Calf Mesa, San Rafael district, Emery Co., Utah, USA
- Chuquicamata, at Quetena, west of Calama, and Alcaparrosa, near Cerritos Bayos, southwest of Calama, Antofagasta, Chile
- Santa Elena mine, Quebrada de La Alcaparrosa, San Juan Province, Argentina
- Saghand, near Yazd, Iran
- Auguste mine, Fuchsberg, near Halle, Saxony-Anhalt, Germany
- Agrokipia, Cyprus
Field-hunting tip
Where it forms: An uncommon mineral in the oxidized zone of pyritic veins, may be formed by alteration of other sulfates. If you start seeing copiapite, cuprocopiapite, butlerite in float, you are in the right ground. Typical habit: prismatic, striated. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify parabutlerite?+
Where is parabutlerite found?+
What rocks look like parabutlerite?+
What minerals are found with parabutlerite?+
What kind of rock does parabutlerite form in?+
What is parabutlerite used for?+
Find parabutlerite on the map
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