Agardite-(Nd) is a rare secondary mineral typically forming delicate, needle-like crystals in radiating sprays or tufts within oxidized copper zones. Collectors prize it for its vibrant yellow-green coloration and aesthetic crystal habit, most famously associated with the historic mines of Laurion, Greece.

Hardness

3-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareMixite Group family

Agardite-(Nd)

Hardness: 3-4
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this agardite-(nd)?

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 agardite-(nd) with a known reference. Agardite-(Nd) sits at Mohs 3-4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Agardite-(Nd) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Agardite-(Nd) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, yellow-green, green.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: acicular crystals, radiating sprays, tufts.

Often confused with

Agardite-(Nd) vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Streak differs — Agardite-(Nd) leaves white, Parnauite leaves pale blue.

How to tell apart: Streak differs — Agardite-(Nd) leaves white, Conichalcite leaves light green.

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Often found alongside agardite-(nd)

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

All properties

Chemical formula: Cu₆Nd(AsO₄)₃(OH)₆·3H₂O
Mohs hardness: 3-4
Density: 3.8-4.0 g/cm³
Colors: Yellow Yellow-green Green
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Hexagonal
Crystal habit: Acicular Crystals, Radiating Sprays, Tufts
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Oxidized Hydrothermal Copper Deposits
Typical price: $20-200 depending on specimen size and quality

Where rockhounds find agardite-(nd)

Classic worldwide localities

Laurion, Greece
Tsumeb, Namibia
Saxony, Germany
Chile

Field-hunting tip

Look in oxidized hydrothermal copper deposits country — that is the host setting where agardite-(nd) typically forms. If you start seeing malachite, azurite, conichalcite in float, you are in the right ground. Field specimens usually show a acicular crystals, radiating sprays, tufts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify agardite-(nd)?+

Mohs hardness is 3-4. It typically shows a vitreous luster. The streak is white. Common colors include yellow, yellow-green, green.

Where is agardite-(nd) found?+

Notable localities include Laurion, Greece; Tsumeb, Namibia; Saxony, Germany; Chile.

How much is agardite-(nd) worth?+

Typical asking prices fall in the range of $20-200 depending on specimen size and quality. Quality, size, and provenance can move individual specimens well outside that range.

Is agardite-(nd) safe to handle?+

It contains toxic constituents. Contains arsenic and copper; avoid inhalation of dust and wash hands thoroughly after handling specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like agardite-(nd)?+

Agardite-(Nd) is most often confused with Mixite, Parnauite, Conichalcite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with agardite-(nd)?+

Agardite-(Nd) commonly co-occurs with Malachite, Azurite, Conichalcite, Goethite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does agardite-(nd) form in?+

Agardite-(Nd) typically forms in oxidized hydrothermal copper deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is agardite-(nd) used for?+

Agardite-(Nd) is used in collector.

Find agardite-(nd) on the map

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