Emmerichite is a very rare member of the mica group found primarily in volcanic ejecta of the Eifel region in Germany. It typically presents as small, yellow to brown platy crystals that are difficult to distinguish from other mica species without sophisticated mineralogical analysis.
Is this emmerichite?
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 emmerichite with a known reference. Emmerichite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Emmerichite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Emmerichite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals.
Often confused with
Emmerichite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside emmerichite
Minerals reported to co-occur with emmerichite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na(Fe³⁺,Mg)₂(Fe³⁺,Al,Ti,Mg)(Si,Al)₄O₁₀(F,O)₂
- Mohs hardness
- 2.5
- Density
- 3.86 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Platy Crystals
- Cleavage
- Perfect Basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Volcanic Rocks
Where rockhounds find emmerichite
Classic worldwide localities
- Germany
Field-hunting tip
Look in volcanic rocks country, the host setting where emmerichite typically forms. If you start seeing sanidine, augite, magnetite in float, you are in the right ground. Field specimens usually show a platy crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify emmerichite?+
Where is emmerichite found?+
What rocks look like emmerichite?+
What minerals are found with emmerichite?+
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What is emmerichite used for?+
Find emmerichite on the map
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