Giacovazzoite is a rare hydrated iron potassium sulfate mineral identified primarily from fumarolic environments. Collectors typically find it as small, orange tabular crystals associated with other sulfate minerals in volcanic settings.
Is this giacovazzoite?
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 giacovazzoite with a known reference. Giacovazzoite 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: yellowish-orange.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: orange, reddish-orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals.
Often confused with
Giacovazzoite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Giacovazzoite leaves yellowish-orange, Jarosite leaves pale yellow; luster reads vitreous on Giacovazzoite and subadamantine to vitreous, resinous on fractures on Jarosite.
How to tell apart: Streak differs, so Giacovazzoite leaves yellowish-orange, Copiapite leaves pale yellow; luster reads vitreous on Giacovazzoite and pearly on {010} on Copiapite.
Often found alongside giacovazzoite
Minerals reported to co-occur with giacovazzoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₅Fe₃O(SO₄)₆·10H₂O
- Mohs hardness
- 2
- Density
- 2.44 g/cm³
- Colors
- Streak
- Yellowish-orange
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular crystals
- Cleavage
- Perfect on {100}, imperfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- fumarolic deposits
Where rockhounds find giacovazzoite
Classic worldwide localities
- Tuscany, Italy
Field-hunting tip
Where it forms: fumarolic deposits. If you start seeing jarosite, gypsum in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify giacovazzoite?+
Where is giacovazzoite found?+
What rocks look like giacovazzoite?+
What minerals are found with giacovazzoite?+
What kind of rock does giacovazzoite form in?+
What is giacovazzoite used for?+
Find giacovazzoite on the map
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