Proxidecagonite is a rare aluminum nickel iron mineral, typically gray to black. It occurs in shock metamorphosed portions of a CV3 carbonaceous chondrite meteorite. It was first described from material found in Russia (meteorite).
Is this proxidecagonite?
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 proxidecagonite with a known reference. Proxidecagonite sits at Mohs 6-7, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Proxidecagonite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Proxidecagonite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: gray, black.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals.
Often confused with
Proxidecagonite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside proxidecagonite
Minerals reported to co-occur with proxidecagonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₃₄Ni₉Fe₂
- Mohs hardness
- 6-7
- Density
- 2.619 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Platy Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Scientific Research
- Host rock
- CV3 Carbonaceous Chondrite Meteorites
Where rockhounds find proxidecagonite
Classic worldwide localities
- Khatyrka meteorite
- Chukotka, Russia
Field-hunting tip
Look in cv3 carbonaceous chondrite meteorites country, the host setting where proxidecagonite typically forms. If you start seeing icosahedrite, hollisterite, stishovite in float, you are in the right ground. Field specimens usually show a platy crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify proxidecagonite?+
Where is proxidecagonite found?+
What rocks look like proxidecagonite?+
What minerals are found with proxidecagonite?+
What kind of rock does proxidecagonite form in?+
What is proxidecagonite used for?+
Find proxidecagonite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
