Ferroaluminoceladonite is a rare phyllosilicate mineral belonging to the mica group. It typically occurs as fine-grained, earthy coatings or inclusions within volcanic rocks and hydrothermal veins. Collectors look for its characteristic soft green hues that distinguish it from more common clay or chlorite minerals.
Is this ferroaluminoceladonite?
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 ferroaluminoceladonite with a known reference. Ferroaluminoceladonite 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. Ferroaluminoceladonite leaves a light green streak.
- 3Read the lusterHold the specimen under a strong light. Ferroaluminoceladonite typically shows a earthy luster.
- 4Match the color rangeCompare against the expected color range: green, bluish-green, brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: micaceous, earthy, massive.
Often confused with
Ferroaluminoceladonite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Ferroaluminoceladonite leaves light green, Celadonite leaves white; luster reads earthy on Ferroaluminoceladonite and dull on Celadonite.
How to tell apart: Streak differs — Ferroaluminoceladonite leaves light green, Glauconite leaves pale green; luster reads earthy on Ferroaluminoceladonite and dull on Glauconite.
How to tell apart: Streak differs — Ferroaluminoceladonite leaves light green, Chlorite leaves white; luster reads earthy on Ferroaluminoceladonite and pearly on Chlorite.
Often found alongside ferroaluminoceladonite
Minerals reported to co-occur with ferroaluminoceladonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KFe³⁺(Mg,Fe²⁺)Si₄O₁₀(OH)₂
- Mohs hardness
- 2
- Density
- 2.8-3.0 g/cm³
- Colors
- Streak
- Light Green
- Luster
- Earthy
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Micaceous, Earthy, Massive
- Cleavage
- Perfect Basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins, Volcanic Rocks
- Typical price
- $15-60 for small specimens
Where rockhounds find ferroaluminoceladonite
Classic worldwide localities
- Czech Republic
- Italy
- Russia
- Germany
Field-hunting tip
Look in hydrothermal veins, volcanic rocks country — that is the host setting where ferroaluminoceladonite typically forms. If you start seeing quartz, calcite, zeolites in float, you are in the right ground. Field specimens usually show a micaceous, earthy, massive habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ferroaluminoceladonite?+
Where is ferroaluminoceladonite found?+
How much is ferroaluminoceladonite worth?+
What rocks look like ferroaluminoceladonite?+
What minerals are found with ferroaluminoceladonite?+
What kind of rock does ferroaluminoceladonite form in?+
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Find ferroaluminoceladonite on the map
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