Mendigite is a rare manganese calcium silicate, typically dark brown. It is a pneumatolitic phase in miarolitic cavities in sanidinite. It was first described from the In den Dellen near Mendig, Eifel Mountains, Rhineland-Palatinate (Rheinland-Pfalz), Germany.
Is this mendigite?
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 mendigite with a known reference. Mendigite sits at Mohs 4.5-5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: brown.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: dark brown.
- 5Look at form & habitCrystal system: triclinic. Typical habit: acicular crystals, fibrous, radial aggregates.
Often confused with
Mendigite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Mendigite is noticeably harder (Mohs 4.5-5 vs. 2.5); streak differs, so Mendigite leaves brown, Linarite leaves pale blue.
How to tell apart: Streak differs, so Mendigite leaves brown, Brochantite leaves pale green.
Often found alongside mendigite
Minerals reported to co-occur with mendigite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mn₂Mn₂MnCa(Si₃O₉)₂
- Mohs hardness
- 4.5-5
- Density
- 3.56 g/cm³
- Colors
- Streak
- Brown
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Acicular crystals, fibrous, radial aggregates
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A pneumatolitic phase in miarolitic cavities in sanidinite
Where rockhounds find mendigite
Classic worldwide localities
- Den Dellen near Mendig, Laacher Lake area, Eifel Mountains, Rhineland-Palatinate (Rheinland-Pfalz), Germany
Field-hunting tip
Where it forms: A pneumatolitic phase in miarolitic cavities in sanidinite. If you start seeing sanidine, nosean, rhodonite in float, you are in the right ground. Typical habit: acicular crystals, fibrous, radial aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify mendigite?+
Where is mendigite found?+
What rocks look like mendigite?+
What minerals are found with mendigite?+
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What is mendigite used for?+
Find mendigite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
