Ferrovorontsovite is an extremely rare thallium-bearing sulfosalt discovered in the Vorontsovskoe gold deposit. It typically occurs as microscopic anhedral grains associated with other sulfide minerals in hydrothermal gold-bearing ores.
Is this ferrovorontsovite?
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 ferrovorontsovite with a known reference. Ferrovorontsovite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Ferrovorontsovite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Ferrovorontsovite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: black, dark gray.
- 5Look at form & habitCrystal system: triclinic. Typical habit: anhedral to subhedral grains.
Often confused with
Ferrovorontsovite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside ferrovorontsovite
Minerals reported to co-occur with ferrovorontsovite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe₃TlAsS₅
- Mohs hardness
- 3.5
- Density
- 4.56 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Triclinic
- Crystal habit
- Anhedral to Subhedral Grains
- Cleavage
- None Observed
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Epithermal Gold Deposits
- Typical price
- n/a
Where rockhounds find ferrovorontsovite
Classic worldwide localities
- Vorontsovskoe gold deposit, Russia
Field-hunting tip
Look in hydrothermal epithermal gold deposits country — that is the host setting where ferrovorontsovite typically forms. If you start seeing pyrite, realgar, orpiment in float, you are in the right ground. Field specimens usually show a anhedral to subhedral grains habit, so train your eye for that shape before scanning the outcrop.







