Clinosafflorite is a rare monoclinic cobalt arsenide that is physically and chemically difficult to distinguish from its orthorhombic counterpart, Safflorite. It typically occurs as silver-white to tin-white massive or granular aggregates in cobalt-bearing hydrothermal veins. Identification usually requires X-ray diffraction or chemical analysis due to its similarity to other cobalt and iron arsenides.
Is this clinosafflorite?
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 clinosafflorite with a known reference. Clinosafflorite sits at Mohs 4.5-5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: tin white, silver white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic, granular, or massive.
Often confused with
Clinosafflorite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Clinosafflorite leaves black, Safflorite leaves grayish black.
How to tell apart: Streak differs, so Clinosafflorite leaves black, Löllingite leaves grayish black.
Often found alongside clinosafflorite
Minerals reported to co-occur with clinosafflorite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CoAs₂
- Mohs hardness
- 4.5-5
- Density
- 7.46 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic, granular, or massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In hydrothermal Co–Ni sulfide ores, typically silver-bearing
Where rockhounds find clinosafflorite
Classic worldwide localities
- London mine, National district, Humboldt Co., Nevada, USA
- Cobalt, Ontario, Canada (type locality)
- Aghbar (Arhbar) mine, Bou Azzer district, Morocco
- Nord mine, Nordmark district, and from near Filipstad, Värmland, Sweden
- Richelsdorf Mountains, Hesse, Germany
- Alva silver mine, Ochil Hills, central Scotland
Field-hunting tip
Where it forms: In hydrothermal Co–Ni sulfide ores, typically silver-bearing. If you start seeing skutterudite, cattierite, cobaltite in float, you are in the right ground. Typical habit: prismatic, granular, or massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify clinosafflorite?+
Where is clinosafflorite found?+
Is clinosafflorite safe to handle?+
What rocks look like clinosafflorite?+
What minerals are found with clinosafflorite?+
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Find clinosafflorite on the map
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