Simonite is an exceptionally rare thallium-arsenic sulfosalt primarily found at the Allchar deposit in North Macedonia. It typically occurs as small orange to reddish-orange 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. Simonite leaves a orange-yellow streak.
- 3Read the lusterHold the specimen under a strong light. Simonite typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: orange, reddish-orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, massive.
Often confused with
Simonite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Streak differs — Simonite leaves orange-yellow, Realgar leaves orange-red; luster reads adamantine on Simonite and resinous on Realgar.

How to tell apart: Streak differs — Simonite leaves orange-yellow, Orpiment leaves yellow; luster reads adamantine on Simonite and resinous on Orpiment.

How to tell apart: Streak differs — Simonite leaves orange-yellow, Lorandite leaves cherry-red; luster reads adamantine on Simonite and metallic on Lorandite.
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
- TlAs₃S₅
- Mohs hardness
- 1.5-2
- Density
- 3.84 g/cm³
- Colors
- Streak
- Orange-yellow
- Luster
- Adamantine
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Massive
- Cleavage
- Perfect in One Direction
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Mineral Deposits
- Typical price
- $50-300+ depending on crystal size and quality
Where rockhounds find simonite
Classic worldwide localities
- Allchar, North Macedonia
Field-hunting tip
Look in hydrothermal mineral deposits country — that is the host setting where simonite typically forms. If you start seeing lorandite, realgar, orpiment in float, you are in the right ground. Field specimens usually show a tabular crystals, massive habit, so train your eye for that shape before scanning the outcrop.

