Meta-aluminite is a rare secondary sulfate mineral formed by the dehydration of aluminite. It typically appears as dull, white earthy masses or crusts within clay deposits and is primarily sought after by advanced collectors of rare sulfate minerals.
Is this meta-aluminite?
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 meta-aluminite with a known reference. Meta-aluminite sits at Mohs 1-2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Meta-aluminite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Meta-aluminite typically shows a dull luster.
- 4Match the color rangeCompare against the expected color range: white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: earthy, massive, or as crusts.
Often confused with
Meta-aluminite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside meta-aluminite
Minerals reported to co-occur with meta-aluminite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₂SO₄(OH)₄·5H₂O
- Mohs hardness
- 1-2
- Density
- 1.8-1.9 g/cm³
- Colors
- Streak
- White
- Luster
- Dull
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Earthy, Massive, Or as Crusts
- Cleavage
- None Observed
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Clay-rich Sedimentary Deposits and Weathering Zones of Aluminous Rocks
- Typical price
- $20-100 per specimen
Where rockhounds find meta-aluminite
Classic worldwide localities
- Halle, Germany
- Newhaven, England
- Epernay, France
Field-hunting tip
Look in clay-rich sedimentary deposits and weathering zones of aluminous rocks country — that is the host setting where meta-aluminite typically forms. If you start seeing aluminite, gypsum, kaolinite in float, you are in the right ground. Field specimens usually show a earthy, massive, or as crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify meta-aluminite?+
Where is meta-aluminite found?+
How much is meta-aluminite worth?+
What rocks look like meta-aluminite?+
What minerals are found with meta-aluminite?+
What kind of rock does meta-aluminite form in?+
What is meta-aluminite used for?+
Find meta-aluminite on the map
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