Cobaltoblödite is a rare cobalt-bearing sulfate typically found as an efflorescence in arid environments. Collectors should look for its characteristic violet-pink color, which distinguishes it from the more common, colorless to greenish-yellow blödite.
Is this cobaltoblödite?
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 cobaltoblödite with a known reference. Cobaltoblödite 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: vitreous.
- 4Match the color rangeCompare against the expected color range: colorless, reddish pink in aggregates.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic to tabular crystals, often as crusts or efflorescences.
Often confused with
Cobaltoblödite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside cobaltoblödite
Minerals reported to co-occur with cobaltoblödite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂Co(SO₄)₂·4H₂O
- Mohs hardness
- 2.5
- Density
- 2.29 g/cm³
- Colors
- ColorlessReddish pink in aggregates
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic to tabular crystals, often as crusts or efflorescences
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Coating the walls of underground mine works, related to post-mining oxidation of primary U deposits of the Colorado Plateau type hosted by sandstones
Where rockhounds find cobaltoblödite
Classic worldwide localities
- Blue Lizard mine, White Canyon district, San Juan County, Utah, USA
Field-hunting tip
Where it forms: Coating the walls of underground mine works, related to post-mining oxidation of primary U deposits of the Colorado Plateau type hosted by sandstones. If you start seeing mn-co-ni-bearing blödite, chalcanthite, gypsum in float, you are in the right ground. Typical habit: prismatic to tabular crystals, often as crusts or efflorescences. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cobaltoblödite?+
Where is cobaltoblödite found?+
Is cobaltoblödite safe to handle?+
What rocks look like cobaltoblödite?+
What minerals are found with cobaltoblödite?+
What kind of rock does cobaltoblödite form in?+
What is cobaltoblödite used for?+
Find cobaltoblödite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
