Aluminoceladonite is a member of the mica group often found as a secondary mineral resulting from the hydrothermal alteration of volcanic rocks. It is noted for its distinctive blue-green color and micaceous, earthy habit, often forming crusts or coatings within vugs and fractures.
Is this aluminoceladonite?
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 aluminoceladonite with a known reference. Aluminoceladonite 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. Aluminoceladonite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Aluminoceladonite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: blue, green, blue-green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: massive, micaceous, earthy, or as fibrous aggregates.
Often confused with
Aluminoceladonite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Luster reads pearly on Aluminoceladonite and dull on Celadonite.
How to tell apart: Streak differs — Aluminoceladonite leaves white, Glauconite leaves pale green; luster reads pearly on Aluminoceladonite and dull on Glauconite.
Often found alongside aluminoceladonite
Minerals reported to co-occur with aluminoceladonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KAl(Mg,Fe²⁺)Si₄O₁₀(OH)₂
- Mohs hardness
- 2
- Density
- 2.8-2.9 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Massive, Micaceous, Earthy, Or as Fibrous Aggregates
- Cleavage
- Perfect Basal
- Rarity
- Uncommon
- Uses
- Collector, Scientific Research
- Host rock
- Hydrothermal Veins, Altered Volcanic Rocks
- Typical price
- $10-50 per specimen
Where rockhounds find aluminoceladonite
Classic worldwide localities
- Hokkaido, Japan
- Srednogorie Zone, Bulgaria
- Kola Peninsula, Russia
- Tuscany, Italy
Field-hunting tip
Look in hydrothermal veins, altered volcanic rocks country — that is the host setting where aluminoceladonite typically forms. If you start seeing quartz, calcite, chlorite in float, you are in the right ground. Field specimens usually show a massive, micaceous, earthy, or as fibrous aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify aluminoceladonite?+
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How much is aluminoceladonite worth?+
What rocks look like aluminoceladonite?+
What minerals are found with aluminoceladonite?+
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Find aluminoceladonite on the map
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