Zaccariniite is a rare platinum-group mineral typically occurring as microscopic grains within chromite deposits. Collectors rarely encounter it except as micro-inclusions in platinum-group alloy suites found in ophiolitic complexes.
Is this zaccariniite?
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 zaccariniite with a known reference. Zaccariniite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Zaccariniite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Zaccariniite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: white, silver-white.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: anhedral grains.
Often confused with
Zaccariniite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Sperrylite is the harder of the two (Mohs 6-7 vs. 3.5-4).
How to tell apart: Laurite is the harder of the two (Mohs 7-7.5 vs. 3.5-4).
How to tell apart: Hollingworthite is the harder of the two (Mohs 6 vs. 3.5-4); streak differs — Zaccariniite leaves black, Hollingworthite leaves grayish-black.
Often found alongside zaccariniite
Minerals reported to co-occur with zaccariniite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- RhNiAs
- Mohs hardness
- 3.5-4
- Density
- 9.24 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Anhedral Grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Ophiolitic Chromitite Deposits
- Typical price
- n/a (rare research-grade material)
Where rockhounds find zaccariniite
Classic worldwide localities
- Ophir Creek, Oregon, USA
- Kempirsai Massif, Kazakhstan
Field-hunting tip
Look in ophiolitic chromitite deposits country — that is the host setting where zaccariniite typically forms. If you start seeing magnetite, chromite, laurite 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 zaccariniite?+
Where is zaccariniite found?+
How much is zaccariniite worth?+
Is zaccariniite safe to handle?+
What rocks look like zaccariniite?+
What minerals are found with zaccariniite?+
What kind of rock does zaccariniite form in?+
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Find zaccariniite on the map
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