Mössbauerite is a rare iron-bearing mineral belonging to the hydrotalcite supergroup, typically formed as an oxidation product of iron-rich carbonates or sulfides. Collectors can identify it by its characteristic hexagonal platy habit and earthy luster, usually found as secondary crusts or fine-grained aggregates in weathered iron ore deposits.
Is this mössbauerite?
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 mössbauerite with a known reference. Mössbauerite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: orange.
- 3Read the lusterHold the specimen under a strong light. Luster: earthy.
- 4Match the color rangeCompare against the expected color range: orange.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy hexagonal crystals, micaceous aggregates, crusts.
Often confused with
Mössbauerite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Goethite is the harder of the two (Mohs 5-5.5 vs. 2-3); streak differs, so Mössbauerite leaves orange, Goethite leaves brownish yellow, yellow-orange, ocher-yellow; luster reads earthy on Mössbauerite and imperfect adamantine metallic to dull earthy; silky when fibrous on Goethite.
How to tell apart: Lepidocrocite is the harder of the two (Mohs 5 vs. 2-3); streak differs, so Mössbauerite leaves orange, Lepidocrocite leaves dull orange; luster reads earthy on Mössbauerite and submetallic on Lepidocrocite.
How to tell apart: Streak differs, so Mössbauerite leaves orange, Hydrotalcite leaves white; luster reads earthy on Mössbauerite and satiny to greasy or waxy on Hydrotalcite.
Often found alongside mössbauerite
Minerals reported to co-occur with mössbauerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe₃³⁺O(OH)₈(CO₃)·nH₂O
- Mohs hardness
- 2-3
- Density
- 2.950 g/cm³
- Colors
- Streak
- Orange
- Luster
- Earthy
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Platy hexagonal crystals, micaceous aggregates, crusts
- Cleavage
- Perfect on {0001}. [synthetic material
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As a secondary mineral in ‘green rust’derived from the oxidation of other members of the fougèrite group in chemically-reduced, waterlogged, intertidal maritime marshes
Where rockhounds find mössbauerite
Classic worldwide localities
- Coastline of Mont Saint-Michel Bay, Brittany and Normandy, France
Field-hunting tip
Where it forms: As a secondary mineral in ‘green rust’derived from the oxidation of other members of the fougèrite group in chemically-reduced, waterlogged, intertidal maritime marshes. If you start seeing trébeurdenite, quartz, feldspars in float, you are in the right ground. Typical habit: platy hexagonal crystals, micaceous aggregates, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify mössbauerite?+
Where is mössbauerite found?+
What rocks look like mössbauerite?+
What minerals are found with mössbauerite?+
What kind of rock does mössbauerite form in?+
What is mössbauerite used for?+
Find mössbauerite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
