Chinchorroite is a rare secondary arsenate mineral that forms as thin, delicate platy crystals or coatings in oxidized zones of ore deposits. It is primarily found in the Cap Garonne mine of France and requires microscopic examination for positive identification due to its scarcity and small crystal size.

Hardness

2-3

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Chinchorroite

Hardness: 2-3
Luster: Vitreous
Streak: White
Transparency: Transparent

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Is this chinchorroite?

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 chinchorroite with a known reference. Chinchorroite 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. Chinchorroite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Chinchorroite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, yellowish-green.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals, crusts.

Often confused with

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

How to tell apart: Legrandite is the harder of the two (Mohs 4.5 vs. 2-3).

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Often found alongside chinchorroite

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

All properties

Chemical formula: NaZn₂(AsO₄)(AsO₃OH)₂·H₂O
Mohs hardness: 2-3
Density: 2.95 g/cm³
Colors: Yellow Yellowish-green
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Platy Crystals, Crusts
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Polymetallic Deposits
Typical price: $50-300 per specimen

Where rockhounds find chinchorroite

Classic worldwide localities

Cap Garonne mine, France

Field-hunting tip

Look in hydrothermal polymetallic deposits country — that is the host setting where chinchorroite typically forms. If you start seeing tennantite, galena, barite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify chinchorroite?+

Mohs hardness is 2-3. It typically shows a vitreous luster. The streak is white. Common colors include yellow, yellowish-green.

Where is chinchorroite found?+

Notable localities include Cap Garonne mine, France.

How much is chinchorroite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is chinchorroite safe to handle?+

It contains toxic constituents. Contains arsenic, which is toxic. Wash hands thoroughly after handling and avoid ingestion or inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like chinchorroite?+

Chinchorroite is most often confused with Köttigite, Legrandite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with chinchorroite?+

Chinchorroite commonly co-occurs with Tennantite, Galena, Barite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does chinchorroite form in?+

Chinchorroite typically forms in hydrothermal polymetallic deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is chinchorroite used for?+

Chinchorroite is used in collector.

Find chinchorroite on the map

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