Misenite is an extremely rare potassium hydrogen sulfate mineral found primarily in volcanic fumaroles. It typically appears as thin crusts or delicate, needle-like crystalline aggregates that are highly sensitive to moisture and must be stored in a dry environment.
Is this misenite?
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 misenite with a known reference. Misenite sits at Mohs 2, 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: pearly to silky.
- 4Match the color rangeCompare against the expected color range: colorless, grayish white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular, aggregates, fibrous.
Often confused with
Misenite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads pearly to silky on Misenite and subvitreous, pearly on {010} cleavages, silky if fibrous on Gypsum.
How to tell apart: Aphthitalite is the harder of the two (Mohs 3 vs. 2); luster reads pearly to silky on Misenite and vitreous to resinous on Aphthitalite.
Often found alongside misenite
Minerals reported to co-occur with misenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₈(SO₄)(SO₃OH)₆
- Mohs hardness
- 2
- Density
- 2.32 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly to silky
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular, aggregates, fibrous
- Cleavage
- On {010}, distinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Very rarely formed under fumarolic conditions
Where rockhounds find misenite
Classic worldwide localities
- Grotto del Solfo fumarole, Cape Miseno, Campi Flegrei, near Naples, and on Vesuvius, Campania, Italy
Field-hunting tip
Where it forms: Very rarely formed under fumarolic conditions. If you start seeing potassium alum, alunogen, halotrichite in float, you are in the right ground. Typical habit: acicular, aggregates, fibrous. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify misenite?+
Where is misenite found?+
What rocks look like misenite?+
What minerals are found with misenite?+
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Find misenite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
