Cobalttsumcorite is a rare secondary mineral belonging to the Tsumcorite group, characterized by its distinct pink to violet-pink coloration. It is typically found as small, tabular crystals or crusts within the oxidized zones of metal-rich ore deposits, most famously at the Tsumeb Mine in Namibia.
Is this cobalttsumcorite?
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 cobalttsumcorite with a known reference. Cobalttsumcorite sits at Mohs 4.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: light brown.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: brown, reddish brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: aggregates, rosette, tabular.
Often confused with
Cobalttsumcorite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Cobalttsumcorite leaves light brown, Tsumcorite leaves yellow; luster reads adamantine on Cobalttsumcorite and vitreous on Tsumcorite.
How to tell apart: Luster reads adamantine on Cobalttsumcorite and vitreous on Cobaltlotharmeyerite.
Often found alongside cobalttsumcorite
Minerals reported to co-occur with cobalttsumcorite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- PbCo₂(AsO₄)₂·2H₂O
- Mohs hardness
- 4.5
- Density
- 5.31 g/cm³
- Colors
- Streak
- Light brown
- Luster
- Adamantine
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Aggregates, rosette, tabular
- Cleavage
- Good on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the oxidation zone of polymetallic ore deposits
Where rockhounds find cobalttsumcorite
Classic worldwide localities
- "Am Roten Berg" mining area, 4.8 km SW of Schneeberg, Germany
Field-hunting tip
Where it forms: In the oxidation zone of polymetallic ore deposits. If you start seeing quartz, mawbyite, cobaltlotharmeyerite in float, you are in the right ground. Typical habit: aggregates, rosette, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cobalttsumcorite?+
Where is cobalttsumcorite found?+
Is cobalttsumcorite safe to handle?+
What rocks look like cobalttsumcorite?+
What minerals are found with cobalttsumcorite?+
What kind of rock does cobalttsumcorite form in?+
What is cobalttsumcorite used for?+
Find cobalttsumcorite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
