Ekatite is a rare arsenic-bearing mineral known primarily from the Khaidarkan mercury-antimony deposit in Kyrgyzstan. It typically forms as delicate, radially arranged prismatic crystals or crusts in hydrothermal environments and requires careful handling due to its arsenic content.
Is this ekatite?
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 ekatite with a known reference. Ekatite sits at Mohs ~3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: brown.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: brownish black.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: acicular, aggregates, striated.
Often confused with
Ekatite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside ekatite
Minerals reported to co-occur with ekatite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Fe,Fe,Zn)₁₂(AsO₃)₆(AsO₃,SiO₃OH)₂(OH)₆
- Mohs hardness
- ~3
- Density
- 4.061 g/cm³
- Colors
- Streak
- Brown
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Hexagonal
- Crystal habit
- Acicular, aggregates, striated
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the oxidized portion of a polymetallic sulfide mineral deposit
Where rockhounds find ekatite
Classic worldwide localities
- Tsumeb, Otjikoto region, Namibia (probably from the second oxidation zone)
Field-hunting tip
Where it forms: In the oxidized portion of a polymetallic sulfide mineral deposit. If you start seeing chalcocite, quartz in float, you are in the right ground. Typical habit: acicular, aggregates, striated. Train your eye for that shape before scanning the outcrop.


