Adranosite-(Fe) is an extremely rare sulfate mineral found primarily in active volcanic fumaroles. It typically forms as small, distinct tabular crystals deposited by volcanic gases at high temperatures.
Is this adranosite-(fe)?
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 adranosite-(fe) with a known reference. Adranosite-(Fe) sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Adranosite-(Fe) leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Adranosite-(Fe) typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellowish-orange.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: tabular crystals.
Often confused with
Adranosite-(Fe) vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside adranosite-(fe)
Minerals reported to co-occur with adranosite-(fe). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (NH₄)₄NaFe₂(SO₄)₄Cl(OH)₂
- Mohs hardness
- 2-3
- Density
- 2.81 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Tetragonal
- Crystal habit
- Tabular Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Fumarolic Deposits
- Typical price
- High-value for specialized systematic mineral collections
Where rockhounds find adranosite-(fe)
Classic worldwide localities
- La Fossa crater, Vulcano, Aeolian Islands, Italy
Field-hunting tip
Look in fumarolic deposits country — that is the host setting where adranosite-(fe) typically forms. If you start seeing sulphur, gypsum, anhydrite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.





