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.

Hardness
1.5-2
Mohs
Luster
Adamantine
Streak
Orange-yellow
Transparency
Translucent

Is this simonite?

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 simonite with a known reference. Simonite sits at Mohs 1.5-2 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Simonite leaves a orange-yellow streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Simonite typically shows a adamantine luster.
  • 4
    Match the color range
    Compare against the expected color range: orange, reddish-orange.
  • 5
    Look at form & habit
    Crystal 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.

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
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.

Common questions

How do you identify simonite?+
Mohs hardness is 1.5-2. It typically shows a adamantine luster. The streak is orange-yellow. Common colors include orange, reddish-orange.
Where is simonite found?+
Notable localities include Allchar, North Macedonia.
How much is simonite worth?+
Typical asking prices fall in the range of $50-300+ depending on crystal size and quality. Quality, size, and provenance can move individual specimens well outside that range.
Is simonite safe to handle?+
It contains toxic constituents. Contains arsenic and thallium, both highly toxic. Handle with gloves and do not ingest or inhale dust; wash hands thoroughly after handling. Handle with care, avoid grinding or breathing dust, and store separately.
What rocks look like simonite?+
Simonite is most often confused with Realgar, Orpiment, Lorandite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with simonite?+
Simonite commonly co-occurs with Lorandite, Realgar, Orpiment, Pyrite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does simonite form in?+
Simonite typically forms in hydrothermal mineral deposits. Working float back to the host body is the standard way to chase a fresh occurrence.
What is simonite used for?+
Simonite is used in collector.

Find simonite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.

Download on the App StoreGet it on Google Play