Arseniopleite is a rare manganese arsenate mineral found almost exclusively in the famous Långban mines of Sweden. Collectors prize it for its rich brownish-red hues and its association with other exotic manganese minerals found in regionally metamorphosed ore bodies.
Is this arseniopleite?
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 arseniopleite with a known reference. Arseniopleite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Arseniopleite leaves a light brown streak.
- 3Read the lusterHold the specimen under a strong light. Arseniopleite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: dark brown, reddish-brown, black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: granular, massive, rarely in tabular crystals.
Often confused with
Arseniopleite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Braunite is the harder of the two (Mohs 6-6.5 vs. 3.5); streak differs — Arseniopleite leaves light brown, Braunite leaves black; luster reads vitreous on Arseniopleite and submetallic on Braunite.
How to tell apart: Hausmannite is the harder of the two (Mohs 5-5.5 vs. 3.5); streak differs — Arseniopleite leaves light brown, Hausmannite leaves brownish-red; luster reads vitreous on Arseniopleite and submetallic on Hausmannite.
Often found alongside arseniopleite
Minerals reported to co-occur with arseniopleite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Mn,Ca,Pb)₃(Mn,Mg)₄(AsO₄)₆(OH)₂
- Mohs hardness
- 3.5
- Density
- 4.05 g/cm³
- Streak
- Light Brown
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Granular, Massive, Rarely in Tabular Crystals
- Cleavage
- None Observed
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphosed Iron-manganese Ore Deposits
- Typical price
- $50-300 per specimen depending on size and quality
Where rockhounds find arseniopleite
Classic worldwide localities
- Långban, Sweden
Field-hunting tip
Look in metamorphosed iron-manganese ore deposits country — that is the host setting where arseniopleite typically forms. If you start seeing hausmannite, barite, berzeliite in float, you are in the right ground. Field specimens usually show a granular, massive, rarely in tabular crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify arseniopleite?+
Where is arseniopleite found?+
How much is arseniopleite worth?+
Is arseniopleite safe to handle?+
What rocks look like arseniopleite?+
What minerals are found with arseniopleite?+
What kind of rock does arseniopleite form in?+
What is arseniopleite used for?+
Find arseniopleite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
