Omsite is an extremely rare nickel sulfate mineral typically found as secondary crusts in oxidized nickel-rich environments. It is characterized by its distinct greenish-yellow color and tendency to form small, delicate aggregates on matrix.
Is this omsite?
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 omsite with a known reference. Omsite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Omsite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Omsite typically shows a resinous luster.
- 4Match the color rangeCompare against the expected color range: yellow, greenish-yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: microcrystalline aggregates.
Often confused with
Omsite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Omsite leaves yellow, Retgersite leaves white; luster reads resinous on Omsite and vitreous on Retgersite.
How to tell apart: Streak differs — Omsite leaves yellow, Morenosite leaves white; luster reads resinous on Omsite and vitreous on Morenosite.
Often found alongside omsite
Minerals reported to co-occur with omsite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ni₂(SO₄)(OH)₂·2H₂O
- Mohs hardness
- 2
- Density
- 4.56 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Resinous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Microcrystalline Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Nickel-sulfide Ore Deposits
- Typical price
- varies significantly by rarity as a type locality specimen
Where rockhounds find omsite
Classic worldwide localities
- Omsite locality, Russia
Field-hunting tip
Look in oxidized nickel-sulfide ore deposits country — that is the host setting where omsite typically forms. If you start seeing gersdorffite, annabergite, millerite in float, you are in the right ground. Field specimens usually show a microcrystalline aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify omsite?+
Where is omsite found?+
How much is omsite worth?+
What rocks look like omsite?+
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Find omsite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
