Aktashite is a rare copper-mercury-arsenic sulfosalt that typically occurs as metallic gray to black masses within hydrothermal veins. It is most frequently found in mercury-rich deposits alongside minerals like cinnabar and realgar. Due to its toxic composition, collectors should store specimens in sealed containers and avoid generating dust.
Is this aktashite?
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 aktashite with a known reference. Aktashite 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. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: grayish black.
- 5Look at form & habitCrystal system: trigonal. Typical habit: anhedral grains, euhedral crystals, microscopic crystals.
Often confused with
Aktashite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside aktashite
Minerals reported to co-occur with aktashite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₆Hg₃As₄S₁₂
- Mohs hardness
- ~3.5
- Density
- 5.5 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Anhedral grains, euhedral crystals, microscopic crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Uncommon, of hydrothermal origin in complex polymetallic As-Hg-bearing deposits
Where rockhounds find aktashite
Classic worldwide localities
- Getchell mine, Potosi district, Humbolt Co., Nevada, USA
- Aktash mercury deposit, Kosh-Agach district, Kurai Range, Altai Mountains (type locality), Russia
- Gal-Khaya deposit, Sakha, Russia
- Lukhumi arsenic deposit, central Caucasus Mountains, Russia
- Vorontsovskoye gold deposit, Serov district, Northern Ural Mountains, Russia
- Chauvai Sb-Hg deposit, Fergana Valley, Alai Range, southern Kyrgyzstan
Field-hunting tip
Where it forms: Uncommon, of hydrothermal origin in complex polymetallic As-Hg-bearing deposits. If you start seeing stibnite, chalcostibite, mercurian tetrahedrite in float, you are in the right ground. Typical habit: anhedral grains, euhedral crystals, microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify aktashite?+
Where is aktashite found?+
Is aktashite safe to handle?+
What rocks look like aktashite?+
What minerals are found with aktashite?+
What kind of rock does aktashite form in?+
What is aktashite used for?+
Find aktashite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
