Metavauxite is a rare phosphate mineral often found as an alteration product of vauxite in tin mines. Collectors should look for its distinctive thin, bladed crystals that typically occur in radiating sprays or as crusts on matrix specimens.
Is this metavauxite?
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 metavauxite with a known reference. Metavauxite 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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to silky in aggregates.
- 4Match the color rangeCompare against the expected color range: colorless, white, light green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: bladed crystals, radial aggregates, crusts.
Often confused with
Metavauxite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside metavauxite
Minerals reported to co-occur with metavauxite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe²⁺Al₂(PO₄)₂(OH)₂·8H₂O
- Mohs hardness
- 3
- Density
- 2.345 g/cm³
- Streak
- White
- Luster
- Vitreous to silky in aggregates
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Bladed crystals, radial aggregates, crusts
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- An uncommon secondary mineral in the oxidized zone of tin mines
Where rockhounds find metavauxite
Classic worldwide localities
- Llallagua and Tazna, Potosí, Bolivia
Field-hunting tip
Where it forms: An uncommon secondary mineral in the oxidized zone of tin mines. If you start seeing vauxite, paravauxite, wavellite in float, you are in the right ground. Typical habit: bladed crystals, radial aggregates, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify metavauxite?+
Where is metavauxite found?+
What rocks look like metavauxite?+
What minerals are found with metavauxite?+
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Find metavauxite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
