Donbassite is a rare dioctahedral chlorite mineral, often found as thin, platy crystals or fine-grained masses in sedimentary basins. It is most frequently identified in coal-bearing strata where it formed through low-temperature hydrothermal processes. Collectors often find it challenging to distinguish from other sheet silicates without X-ray diffraction analysis due to its visual similarity to fine-grained mica.
Is this donbassite?
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 donbassite with a known reference. Donbassite 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: white.
- 3Read the lusterHold the specimen under a strong light. Luster: pearly.
- 4Match the color rangeCompare against the expected color range: white, greenish white, yellowish white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: earthy, granular.
Often confused with
Donbassite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside donbassite
Minerals reported to co-occur with donbassite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₂(Si₃Al)O₁₀(OH)₂·Al₂.₃₃₃₃(OH)₆
- Mohs hardness
- 2.5
- Density
- 2.63 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Earthy, granular
- Cleavage
- One perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the lode walls and crushed zones in ore veins and as coatings on slickensides of coals
Where rockhounds find donbassite
Classic worldwide localities
- A number of places in the Donets Basin, as at Nagol'no Tarasovka, Ukraine
- Novaya Zemlya, Arctic Ocean
- Kesselberg, Black Forest, Germany
- Saint-Paul-de-Fenouillet, Pyrénées-Orientales, France
- Namivu, Alto Ligonha district, Mozambique
- Szabo Blu®, Scott Glacier, Antarctica
Field-hunting tip
Where it forms: In the lode walls and crushed zones in ore veins and as coatings on slickensides of coals. If you start seeing quartz, pyrite, siderite in float, you are in the right ground. Typical habit: earthy, granular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify donbassite?+
Where is donbassite found?+
What rocks look like donbassite?+
What minerals are found with donbassite?+
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What is donbassite used for?+
Find donbassite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
