Simonite is an exceptionally rare thallium-arsenic sulfosalt primarily found at the Allchar deposit in North Macedonia. It typically occurs as small red tabular crystals associated with other rare thallium species.
Is this simonite?
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 simonite with a known reference. Simonite sits at Mohs 1.5-2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: orange-yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: red.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: irregular grains.
Often confused with
Simonite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Simonite leaves orange-yellow, Realgar leaves red-orange to red; luster reads adamantine on Simonite and resinous to greasy on Realgar.
How to tell apart: Streak differs, so Simonite leaves orange-yellow, Orpiment leaves pale lemon-yellow; luster reads adamantine on Simonite and resinous, pearly on cleavage surface on Orpiment.
How to tell apart: Streak differs, so Simonite leaves orange-yellow, Lorándite leaves cherry-red; luster reads adamantine on Simonite and metallic, adamantine on Lorándite.
Often found alongside simonite
Minerals reported to co-occur with simonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- TlHgAs₃S₆
- Mohs hardness
- 1.5-2
- Density
- 5.036 g/cm³
- Colors
- Streak
- Orange-yellow
- Luster
- Adamantine
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Irregular grains
- Cleavage
- Perfect in one direction
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As inclusions in rebulite
Where rockhounds find simonite
Classic worldwide localities
- Alšar (Allchar), near Rošden, Macedonia (type locality)
Field-hunting tip
Where it forms: As inclusions in rebulite. If you start seeing rebulite, christite or routhierite, parapierrotite in float, you are in the right ground. Typical habit: irregular grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify simonite?+
Where is simonite found?+
Is simonite safe to handle?+
What rocks look like simonite?+
What minerals are found with simonite?+
What kind of rock does simonite form in?+
What is simonite used for?+
Find simonite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
