Cobaltneustädtelite is a very rare member of the mixite group that primarily occurs as fine needle-like crystals or radial sprays. It is typically found in the oxidized zones of arsenic-rich hydrothermal veins and is highly prized by advanced mineral collectors for its rarity.
Is this cobaltneustädtelite?
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 cobaltneustädtelite with a known reference. Cobaltneustädtelite 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.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular.
Often confused with
Cobaltneustädtelite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Cobaltneustädtelite leaves light brown, Mixite leaves pale bluish green; luster reads adamantine on Cobaltneustädtelite and vitreous, silky in aggregates on Mixite.
How to tell apart: Cobaltneustädtelite is noticeably harder (Mohs 4.5 vs. ~2); streak differs, so Cobaltneustädtelite leaves light brown, Parnauite leaves greenish white; luster reads adamantine on Cobaltneustädtelite and vitreous on Parnauite.
Often found alongside cobaltneustädtelite
Minerals reported to co-occur with cobaltneustädtelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Bi₂Fe(Co,Fe)(AsO₄)₂(O,OH)₄
- Mohs hardness
- 4.5
- Density
- 5.81 g/cm³
- Colors
- Streak
- Light brown
- Luster
- Adamantine
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Tabular
- Cleavage
- Good on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In vugs in quartz collected on waste piles from mining activity
Where rockhounds find cobaltneustädtelite
Classic worldwide localities
- Studied material from the dumps of the Güldener Falk mine near Schneeberg-Neustädtel, Saxony, Germany
- Other mines with confirmed occurrence in the same district are Siebenschleken, Junge Kalbe, Friedefürst, and Peter und Paul
Field-hunting tip
Where it forms: In vugs in quartz collected on waste piles from mining activity. If you start seeing neustädtelite, quartz, preisingerite in float, you are in the right ground. Typical habit: tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cobaltneustädtelite?+
Where is cobaltneustädtelite found?+
Is cobaltneustädtelite safe to handle?+
What rocks look like cobaltneustädtelite?+
What minerals are found with cobaltneustädtelite?+
What kind of rock does cobaltneustädtelite form in?+
What is cobaltneustädtelite used for?+
Find cobaltneustädtelite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
