Kobyashevite is a rare secondary copper sulfate mineral typically found as delicate, pale blue platy crystals or thin crusts in the oxidized zones of copper deposits. It is often identified by its association with other secondary copper minerals and its tendency to occur in small, distinctively blue clusters that require magnification to fully appreciate.
Is this kobyashevite?
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 kobyashevite with a known reference. Kobyashevite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: bluish green.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: bluish-green, turquoise-blue.
- 5Look at form & habitCrystal system: triclinic. Typical habit: platy crystals, crusts, aggregates.
Often confused with
Kobyashevite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Brochantite is the harder of the two (Mohs 3.5-4 vs. 2.5); streak differs, so Kobyashevite leaves bluish green, Brochantite leaves pale green.
How to tell apart: Streak differs, so Kobyashevite leaves bluish green, Langite leaves greenish blue.
How to tell apart: Streak differs, so Kobyashevite leaves bluish green, Posnjakite leaves pale blue.
Often found alongside kobyashevite
Minerals reported to co-occur with kobyashevite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₅(SO₄)₂(OH)₆·4H₂O
- Mohs hardness
- 2.5
- Density
- 3.16 g/cm³
- Colors
- Bluish-greenTurquoise-blue
- Streak
- Bluish green
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Platy crystals, crusts, aggregates
- Cleavage
- Distinct on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As a secondary mineral in pyrite-chalcopyrite veins cutting fenites in an alkaline igneous complex
Where rockhounds find kobyashevite
Classic worldwide localities
- Kapital’naya mine, Vishnevye Mountains, Chelyabinsk Oblast’, South Urals, Russia
Field-hunting tip
Where it forms: As a secondary mineral in pyrite-chalcopyrite veins cutting fenites in an alkaline igneous complex. If you start seeing calcite, quartz in float, you are in the right ground. Typical habit: platy crystals, crusts, aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify kobyashevite?+
Where is kobyashevite found?+
Is kobyashevite safe to handle?+
What rocks look like kobyashevite?+
What minerals are found with kobyashevite?+
What kind of rock does kobyashevite form in?+
What is kobyashevite used for?+
Find kobyashevite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
