Manganarsite is an extremely rare manganese arsenate mineral known primarily from the Långban mining district in Sweden. It typically occurs as tiny, transparent, yellow tabular crystals within manganese ore assemblages and requires magnification for proper identification.
Is this manganarsite?
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 manganarsite with a known reference. Manganarsite 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: pale pink.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: pink brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: hexagonal, massive.
Often confused with
Manganarsite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Armangite is the harder of the two (Mohs ~4 vs. ~3); streak differs, so Manganarsite leaves pale pink, Armangite leaves brown; luster reads vitreous on Manganarsite and adamantine on Armangite.
How to tell apart: Manganberzeliite is the harder of the two (Mohs 4.5-5 vs. ~3); streak differs, so Manganarsite leaves pale pink, Manganberzeliite leaves white to yellow-orange; luster reads vitreous on Manganarsite and resinous on Manganberzeliite.
Often found alongside manganarsite
Minerals reported to co-occur with manganarsite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mn₃As₂O₄(OH)₄
- Mohs hardness
- ~3
- Density
- 3.64 g/cm³
- Colors
- Streak
- Pale pink
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Trigonal
- Crystal habit
- Hexagonal, massive
- Cleavage
- {0001}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Coating armangite, and filling fractures, in a museum specimen from a metamorphosed Fe–Mn deposit
Where rockhounds find manganarsite
Classic worldwide localities
- Långban, Värmland, Sweden
Field-hunting tip
Where it forms: Coating armangite, and filling fractures, in a museum specimen from a metamorphosed Fe–Mn deposit. If you start seeing calcite, barite, hematite in float, you are in the right ground. Typical habit: hexagonal, massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify manganarsite?+
Where is manganarsite found?+
Is manganarsite safe to handle?+
What rocks look like manganarsite?+
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Find manganarsite on the map
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