Marrite is a rare lead-silver-arsenic sulfosalt mineral primarily known from the famous Lengenbach Quarry in Switzerland. It typically occurs as small, dark, metallic tabular crystals embedded in dolomite and is highly prized by systematic mineral collectors.
Is this marrite?
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 marrite with a known reference. Marrite 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. Marrite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Marrite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: dark gray, black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, massive, granular.
Often confused with
Marrite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Marrite leaves black, Sartorite leaves chocolate-brown.
How to tell apart: Marrite is noticeably harder (Mohs 3 vs. 1.5-2); streak differs — Marrite leaves black, Hutchinsonite leaves red; luster reads metallic on Marrite and adamantine on Hutchinsonite.
Often found alongside marrite
Minerals reported to co-occur with marrite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- PbAgAsS₃
- Mohs hardness
- 3
- Density
- 4.85 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Massive, Granular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Dolomitic Marble Cavities
- Typical price
- $50-500 thumbnail size
Where rockhounds find marrite
Classic worldwide localities
- Binnental, Valais, Switzerland
Field-hunting tip
Look in dolomitic marble cavities country — that is the host setting where marrite typically forms. If you start seeing sartorite, realgar, pyrite in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find marrite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
