Mendozavilite-NaFe is a rare phosphate-molybdate mineral typically found as a secondary oxidation product in molybdenum-rich ore deposits. Collectors primarily find it as thin, dusty, or earthy yellow-to-orange coatings on host rock rather than distinct large crystals.

Hardness

2-3

Mohs

Luster

Earthy

Streak

Yellow

Transparency

Opaque

mineralrareMendozavilite Group family

Mendozavilite-NaFe

Hardness: 2-3
Luster: Earthy
Streak: Yellow
Transparency: Opaque

Is this mendozavilite-nafe?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch mendozavilite-nafe with a known reference. Mendozavilite-NaFe sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Mendozavilite-NaFe leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Mendozavilite-NaFe typically shows a earthy luster.
4
Match the color range
Compare against the expected color range: yellow, orange, brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: powdery, earthy crusts, microcrystalline aggregates.

Often confused with

Mendozavilite-NaFe vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Luster reads earthy on Mendozavilite-NaFe and silky on Molybdite.

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Often found alongside mendozavilite-nafe

Minerals reported to co-occur with mendozavilite-nafe. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: NaFe₄(PO₄)₃(Mo,W)₂O₈(OH)₂(H₂O)₁₄
Mohs hardness: 2-3
Density: 3.36 g/cm³
Colors: Yellow Orange Brown
Streak: Yellow
Luster: Earthy
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Powdery, Earthy Crusts, Microcrystalline Aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Molybdenum-bearing Deposits
Typical price: $50-200 thumbnail

Where rockhounds find mendozavilite-nafe

Classic worldwide localities

Mendoza, Argentina
Chile
Nevada, USA

Field-hunting tip

Look in oxidized zones of molybdenum-bearing deposits country — that is the host setting where mendozavilite-nafe typically forms. If you start seeing jarosite, molybdenite, goethite in float, you are in the right ground. Field specimens usually show a powdery, earthy crusts, microcrystalline aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify mendozavilite-nafe?+

Mohs hardness is 2-3. It typically shows a earthy luster. The streak is yellow. Common colors include yellow, orange, brown.

Where is mendozavilite-nafe found?+

Notable localities include Mendoza, Argentina; Chile; Nevada, USA.

How much is mendozavilite-nafe worth?+

Typical asking prices fall in the range of $50-200 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like mendozavilite-nafe?+

Mendozavilite-NaFe is most often confused with Mendozavilite-KCa, Molybdite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with mendozavilite-nafe?+

Mendozavilite-NaFe commonly co-occurs with Jarosite, Molybdenite, Goethite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mendozavilite-nafe form in?+

Mendozavilite-NaFe typically forms in oxidized zones of molybdenum-bearing deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mendozavilite-nafe used for?+

Mendozavilite-NaFe is used in collector.

Find mendozavilite-nafe on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.