Omeiite is an extremely rare osmium arsenide found primarily in platinum-group element bearing deposits. It typically occurs as small, metallic grains, often requiring microscopic study for positive identification due to its similarity to other arsenide minerals.
Is this omeiite?
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 omeiite with a known reference. Omeiite sits at Mohs 7, 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: steel gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: anhedral to subhedral grains.
Often confused with
Omeiite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside omeiite
Minerals reported to co-occur with omeiite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- OsAs₂
- Mohs hardness
- 7
- Density
- 11.2 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Anhedral to subhedral grains
- Cleavage
- Parallel to elongation
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a Cu–Ni sulfide deposit associated with an ultramafic body
Where rockhounds find omeiite
Classic worldwide localities
- Danba, Sichuan Province, China (type locality)
Field-hunting tip
Where it forms: In a Cu–Ni sulfide deposit associated with an ultramafic body. If you start seeing pyrrhotite, pentlandite, chalcopyrite in float, you are in the right ground. Typical habit: anhedral to subhedral grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify omeiite?+
Where is omeiite found?+
Is omeiite safe to handle?+
What rocks look like omeiite?+
What minerals are found with omeiite?+
What kind of rock does omeiite form in?+
What is omeiite used for?+
Find omeiite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
