Campostriniite is an extremely rare sulfate mineral found exclusively in the fumaroles of the La Fossa crater on Vulcano Island, Italy. It typically occurs as small, yellow, prismatic crystals associated with other bismuth and lead-bearing secondary minerals. It is highly sought after by advanced mineral collectors specializing in rare volcanic fumarole species.
Is this campostriniite?
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 campostriniite with a known reference. Campostriniite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Campostriniite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Campostriniite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, brownish-yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Campostriniite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside campostriniite
Minerals reported to co-occur with campostriniite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Bi,Pb)₄O₄(SO₄)(OH)₂
- Mohs hardness
- 3
- Density
- 2.79 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Fumarolic Deposits
- Typical price
- $100-500+ per specimen
Where rockhounds find campostriniite
Classic worldwide localities
- La Fossa crater, Vulcano, Aeolian Islands, Italy
Field-hunting tip
Look in fumarolic deposits country — that is the host setting where campostriniite typically forms. If you start seeing anglesite, demesmaekerite, alunite in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify campostriniite?+
Where is campostriniite found?+
How much is campostriniite worth?+
Is campostriniite safe to handle?+
What rocks look like campostriniite?+
What minerals are found with campostriniite?+
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Find campostriniite on the map
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