Gabrielite is an extremely rare sulfosalt mineral found almost exclusively in the Binn Valley of Switzerland. It typically forms small, reddish, tabular crystals embedded in dolomitic marble or associated with other rare arsenic-bearing sulfosalts.

Hardness
2
Mohs
Luster
Resinous
Streak
Yellow-orange
Transparency
Translucent

Is this gabrielite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try to scratch gabrielite with a known reference. Gabrielite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Gabrielite leaves a yellow-orange streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Gabrielite typically shows a resinous luster.
  • 4
    Match the color range
    Compare against the expected color range: dark red, brownish-red.
  • 5
    Look at form & habit
    Crystal system: triclinic. Typical habit: tabular crystals.

Often confused with

Gabrielite vs. its common look-alikes — and how to tell them apart in the field.

Often found alongside gabrielite

Minerals reported to co-occur with gabrielite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula
Tl₂AgCuAs₃S₆
Mohs hardness
2
Density
4.46 g/cm³
Streak
Yellow-orange
Luster
Resinous
Transparency
Translucent
Crystal system
Triclinic
Crystal habit
Tabular Crystals
Cleavage
None Observed
Rarity
Rare
Uses
Collector
Host rock
Dolomitic Limestone in Hydrothermal Deposits
Typical price
$200-1000+ per specimen

Where rockhounds find gabrielite

Classic worldwide localities

  • Lengenbach Quarry, Binn Valley, Switzerland

Field-hunting tip

Look in dolomitic limestone in hydrothermal deposits country — that is the host setting where gabrielite typically forms. If you start seeing realgar, orpiment, sartorite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify gabrielite?+
Mohs hardness is 2. It typically shows a resinous luster. The streak is yellow-orange. Common colors include dark red, brownish-red.
Where is gabrielite found?+
Notable localities include Lengenbach Quarry, Binn Valley, Switzerland.
How much is gabrielite worth?+
Typical asking prices fall in the range of $200-1000+ per specimen. Quality, size, and provenance can move individual specimens well outside that range.
Is gabrielite safe to handle?+
It contains toxic constituents. Contains thallium, silver, copper, and arsenic. Toxic if inhaled or ingested; handle with extreme caution and wash hands thoroughly after contact. Handle with care, avoid grinding or breathing dust, and store separately.
What rocks look like gabrielite?+
Gabrielite is most often confused with Smithite, Hutchinsonite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with gabrielite?+
Gabrielite commonly co-occurs with Realgar, Orpiment, Sartorite, Tennantite, Pyrite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does gabrielite form in?+
Gabrielite typically forms in dolomitic limestone in hydrothermal deposits. Working float back to the host body is the standard way to chase a fresh occurrence.
What is gabrielite used for?+
Gabrielite is used in collector.

Find gabrielite on the map

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