Baumhauerite II is a rare sulfosalt mineral that is a structural polytype of the more common Baumhauerite. It is primarily found in the classic Lengenbach locality in Switzerland, occurring as small, lead-gray tabular crystals within dolomitic marble. Collectors value it for its complexity and rarity in the sulfosalt group.
Is this baumhauerite ii?
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 baumhauerite ii with a known reference. Baumhauerite II 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: reddish-brown.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: lead-gray, iron-black.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular crystals, striated.
Often confused with
Baumhauerite II vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Baumhauerite II leaves reddish-brown, Baumhauerite leaves chocolate-brown.
How to tell apart: Streak differs, so Baumhauerite II leaves reddish-brown, Sartorite leaves chocolate-brown.
How to tell apart: Streak differs, so Baumhauerite II leaves reddish-brown, Dufrénoysite leaves reddish brown to chocolate-brown; luster reads metallic on Baumhauerite II and submetallic on Dufrénoysite.
Often found alongside baumhauerite ii
Minerals reported to co-occur with baumhauerite ii. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₃As₄S₉
- Mohs hardness
- 3
- Density
- 5.36 g/cm³
- Colors
- Streak
- Reddish-brown
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Triclinic
- Crystal habit
- Tabular crystals, striated
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- dolomite marble
Where rockhounds find baumhauerite ii
Classic worldwide localities
- Lengenbach Quarry, Binntal, Switzerland
Field-hunting tip
Where it forms: dolomite marble. If you start seeing realgar, orpiment, pyrite in float, you are in the right ground. Typical habit: tabular crystals, striated. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify baumhauerite ii?+
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What rocks look like baumhauerite ii?+
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Find baumhauerite ii on the map
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