Rüdlingerite is a very rare manganese arsenate mineral discovered in the manganese ore deposits of Switzerland. It typically forms thin, orange-colored tabular crystals embedded in quartz or associated with iron oxides. Collectors prize this species for its extremely limited type locality and distinct crystalline form.
Is this rüdlingerite?
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 rüdlingerite with a known reference. Rüdlingerite 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. Streak: yellowish white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: orange, yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals.
Often confused with
Rüdlingerite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Rüdlingerite is noticeably harder (Mohs 3.5 vs. 2-2.5); streak differs, so Rüdlingerite leaves yellowish white, Vantasselite leaves white; luster reads vitreous on Rüdlingerite and pearly on cleavages on Vantasselite.
How to tell apart: Arseniosiderite is the harder of the two (Mohs 4.5 vs. 3.5); streak differs, so Rüdlingerite leaves yellowish white, Arseniosiderite leaves ocher-yellow; luster reads vitreous on Rüdlingerite and submetallic to silky on Arseniosiderite.
Often found alongside rüdlingerite
Minerals reported to co-occur with rüdlingerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mn₂VAsO₇(H₂O)₂
- Mohs hardness
- 3.5
- Density
- 3.28 g/cm³
- Streak
- Yellowish white
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular crystals
- Cleavage
- Perfect on (001)
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a small Alpine metamorphic Mn deposit in dolomitic marble
Where rockhounds find rüdlingerite
Classic worldwide localities
- Fianel mine, Val Ferrera, Grisons, Switzerland (type locality) and the Valletta mine, Canosio, Cuneo, Piedmont, Italy
Field-hunting tip
Where it forms: In a small Alpine metamorphic Mn deposit in dolomitic marble. If you start seeing ansermetite, fe oxyhydroxide, braccoite in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify rüdlingerite?+
Where is rüdlingerite found?+
Is rüdlingerite safe to handle?+
What rocks look like rüdlingerite?+
What minerals are found with rüdlingerite?+
What kind of rock does rüdlingerite form in?+
What is rüdlingerite used for?+
Find rüdlingerite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
