Aluminopyracmonite is a rare ammonium aluminum sulfate mineral found primarily in volcanic fumarolic environments. It typically occurs as delicate, white to colorless crusts or efflorescences around active volcanic vents and is highly water-soluble.
Is this aluminopyracmonite?
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 aluminopyracmonite with a known reference. Aluminopyracmonite 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. Aluminopyracmonite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Aluminopyracmonite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: crusts, efflorescences.
Often confused with
Aluminopyracmonite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside aluminopyracmonite
Minerals reported to co-occur with aluminopyracmonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (NH₄)₃Al(SO₄)₃
- Mohs hardness
- 2.5
- Density
- 2.33 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Crusts, Efflorescences
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Fumarolic Deposits
- Typical price
- $50-200 small specimen
Where rockhounds find aluminopyracmonite
Classic worldwide localities
- La Fossa crater, Vulcano, Aeolian Islands, Italy
Field-hunting tip
Look in fumarolic deposits country — that is the host setting where aluminopyracmonite typically forms. If you start seeing mascagnite, tschermigite, sulfur in float, you are in the right ground. Field specimens usually show a crusts, efflorescences habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify aluminopyracmonite?+
Where is aluminopyracmonite found?+
How much is aluminopyracmonite worth?+
What rocks look like aluminopyracmonite?+
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Find aluminopyracmonite on the map
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