Rebulite is an extremely rare lead-arsenic sulfosalt found almost exclusively at the Allchar deposit in North Macedonia. It typically presents as dark gray prismatic crystals or massive inclusions alongside other arsenic minerals, requiring careful handling due to its toxic chemical composition.
Is this rebulite?
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 rebulite with a known reference. Rebulite sits at Mohs 2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: brownish red.
- 3Read the lusterHold the specimen under a strong light. Luster: submetallic to metallic.
- 4Match the color rangeCompare against the expected color range: dark gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic, massive, or granular.
Often confused with
Rebulite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Rebulite leaves brownish red, Realgar leaves red-orange to red; luster reads submetallic to metallic on Rebulite and resinous to greasy on Realgar.
How to tell apart: Streak differs, so Rebulite leaves brownish red, Orpiment leaves pale lemon-yellow; luster reads submetallic to metallic on Rebulite and resinous, pearly on cleavage surface on Orpiment.
Often found alongside rebulite
Minerals reported to co-occur with rebulite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Tl₅Sb₅As₈S₂₂
- Mohs hardness
- 2
- Density
- 4.81 g/cm³
- Colors
- Streak
- Brownish red
- Luster
- Submetallic to metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic, massive, or granular
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a hydrothermal As–Tl deposit
Where rockhounds find rebulite
Classic worldwide localities
- Alšar (Allchar), near Rošden, Macedonia (type locality)
Field-hunting tip
Where it forms: In a hydrothermal As–Tl deposit. If you start seeing simonite, realgar in float, you are in the right ground. Typical habit: prismatic, massive, or granular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify rebulite?+
Where is rebulite found?+
Is rebulite safe to handle?+
What rocks look like rebulite?+
What minerals are found with rebulite?+
What kind of rock does rebulite form in?+
What is rebulite used for?+
Find rebulite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
