Ferchromide is an extremely rare iron-chromium alloy typically found as microscopic inclusions within chromite grains in ophiolitic rocks. Due to its metallic nature and rarity, it is almost exclusively a micro-mineral for advanced collectors and researchers studying geological mantle processes.
Is this ferchromide?
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 ferchromide with a known reference. Ferchromide sits at Mohs 6.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: gray.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: gray white.
- 5Look at form & habitCrystal system: cubic. Typical habit: grains.
Often confused with
Ferchromide vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside ferchromide
Minerals reported to co-occur with ferchromide. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cr₁.₅Fe₀.₂
- Mohs hardness
- 6.5
- Density
- 6.18 g/cm³
- Colors
- Streak
- Gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In quartz veins within brecciated amphibolites and schist
Where rockhounds find ferchromide
Classic worldwide localities
- Efim Area, Kumak ore field, Orenburgskaya Oblast', Urals Region, Russia (type locality)
Field-hunting tip
Where it forms: In quartz veins within brecciated amphibolites and schist. If you start seeing iron, copper, bismuth in float, you are in the right ground. Typical habit: grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ferchromide?+
Where is ferchromide found?+
What rocks look like ferchromide?+
What minerals are found with ferchromide?+
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What is ferchromide used for?+
Find ferchromide on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
