Iquiqueite is an extremely rare chromate-iodate mineral found primarily in the hyper-arid nitrate fields of northern Chile. Collectors prize it for its vibrant yellow fluorescence under short-wave ultraviolet light, although specimens are often quite small and fragile.
Is this iquiqueite?
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 iquiqueite with a known reference. Iquiqueite sits at Mohs 1.5-2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: yellow.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy crystals, crusts, radial aggregates.
Often confused with
Iquiqueite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Dietzeite is the harder of the two (Mohs 3.5 vs. 1.5-2); streak differs, so Iquiqueite leaves yellow, Dietzeite leaves light yellow.
How to tell apart: Lautarite is the harder of the two (Mohs 3.5-4 vs. 1.5-2); streak differs, so Iquiqueite leaves yellow, Lautarite leaves white.
Often found alongside iquiqueite
Minerals reported to co-occur with iquiqueite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₃Na₄Mg(CrO₄)B₂₄O₃₉(OH)·12H₂O
- Mohs hardness
- 1.5-2
- Density
- 2.05 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Platy crystals, crusts, radial aggregates
- Cleavage
- {0001}, perfect; {1010}, imperfect
- Fluorescence
- Bright yellow under SW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A widespread but very minor constituent of nitrate deposits in saline cemented alluvium and fractured bedrock
Where rockhounds find iquiqueite
Classic worldwide localities
- First samples appear to have originated from the vicinity of Zapiga, Tarapacá, Chile
- Later found at Salar del Miraje, Maria Elena, Tamarugal Pampa, Antofagasta, Chile
Field-hunting tip
Where it forms: A widespread but very minor constituent of nitrate deposits in saline cemented alluvium and fractured bedrock. If you start seeing nitratine, halite, niter in float, you are in the right ground. Typical habit: platy crystals, crusts, radial aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
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Find iquiqueite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
