Ferhodsite is a rare member of the cobaltite group, characterized by its iron-dominant chemistry relative to cobalt. It is typically found as small, non-descript grains in cobalt-rich hydrothermal vein deposits. Due to its close physical resemblance to other sulfarsenides, positive identification usually requires advanced analysis like SEM-EDS or X-ray diffraction.
Is this ferhodsite?
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 ferhodsite with a known reference. Ferhodsite sits at Mohs 5-6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Ferhodsite leaves a grey-black streak.
- 3Read the lusterHold the specimen under a strong light. Ferhodsite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: white, silver-white.
- 5Look at form & habitCrystal system: cubic. Typical habit: anhedral grains.
Often confused with
Ferhodsite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Ferhodsite leaves grey-black, Cobaltite leaves greyish-black.
How to tell apart: Streak differs, so Ferhodsite leaves grey-black, Arsenopyrite leaves black.
How to tell apart: Streak differs, so Ferhodsite leaves grey-black, Gersdorffite leaves grayish-black.
Often found alongside ferhodsite
Minerals reported to co-occur with ferhodsite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Fe,Co)AsS
- Mohs hardness
- 5-6
- Density
- 6.57 g/cm³
- Colors
- Streak
- Grey-black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Anhedral Grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins
- Typical price
- $50-300 per specimen
Where rockhounds find ferhodsite
Classic worldwide localities
- Bou Azzer, Morocco
Field-hunting tip
Look in hydrothermal veins country, the host setting where ferhodsite typically forms. If you start seeing cobaltite, skutterudite, erythrite in float, you are in the right ground. Field specimens usually show a anhedral grains habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ferhodsite?+
Where is ferhodsite found?+
How much is ferhodsite worth?+
Is ferhodsite safe to handle?+
What rocks look like ferhodsite?+
What minerals are found with ferhodsite?+
What kind of rock does ferhodsite form in?+
What is ferhodsite used for?+
Find ferhodsite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
