Sicherite is a very rare silver thallium arsenic sulfosalt discovered in the famous Lengenbach Quarry in Switzerland. It typically occurs as minute, dark grey metallic grains embedded within dolomitic marble and is primarily of interest to advanced micromounters and mineral collectors.
Is this sicherite?
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 sicherite with a known reference. Sicherite 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: dark brown-red.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: dark gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: aggregates, anhedral grains.
Often confused with
Sicherite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Sicherite leaves dark brown-red, Gratonite leaves black.
How to tell apart: Streak differs, so Sicherite leaves dark brown-red, Sartorite leaves chocolate-brown.
How to tell apart: Sicherite is noticeably harder (Mohs ~3 vs. 1.5-2); streak differs, so Sicherite leaves dark brown-red, Smithite leaves vermilion; luster reads metallic on Sicherite and adamantine on Smithite.
Often found alongside sicherite
Minerals reported to co-occur with sicherite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- TlAg₂(As,Sb)₃S₆
- Mohs hardness
- ~3
- Density
- 5.26 g/cm³
- Colors
- Streak
- Dark brown-red
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Aggregates, anhedral grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In cavities in dolomitic rock; the product of late-stage Tl-As-bearing hydrothermal solutions during metamorphism
Where rockhounds find sicherite
Classic worldwide localities
- Lengenbach quarry, Binntal, Valais Canton, Switzerland
Field-hunting tip
Where it forms: In cavities in dolomitic rock; the product of late-stage Tl-As-bearing hydrothermal solutions during metamorphism. If you start seeing realgar, hutchinsonite, hatchite in float, you are in the right ground. Typical habit: aggregates, anhedral grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify sicherite?+
Where is sicherite found?+
Is sicherite safe to handle?+
What rocks look like sicherite?+
What minerals are found with sicherite?+
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What is sicherite used for?+
Find sicherite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
