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.
Is this agardite-(nd)?
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 agardite-(nd) with a known reference. Agardite-(Nd) sits at Mohs <3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous; silky (aggregates).
- 4Match the color rangeCompare against the expected color range: grass green, sky blue.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: aggregates, prismatic, radial.
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, so Agardite-(Nd) leaves white, Mixite leaves pale bluish green.
How to tell apart: Agardite-(Nd) is noticeably harder (Mohs <3 vs. ~2); streak differs, so Agardite-(Nd) leaves white, Parnauite leaves greenish white.
How to tell apart: Conichalcite is the harder of the two (Mohs 4.5 vs. <3); streak differs, so Agardite-(Nd) leaves white, Conichalcite leaves green.
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
- Density
- 3.72 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous; silky (aggregates)
- Transparency
- Transparent
- Crystal system
- Hexagonal
- Crystal habit
- Aggregates, prismatic, radial
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the oxidation zone of polymetallic sulfide deposits
Where rockhounds find agardite-(nd)
Classic worldwide localities
- Hilarion Mine, Agios Konstantinos (Kamariza), Lavrion, Attikí Prefecture, Greece
Field-hunting tip
Where it forms: In the oxidation zone of polymetallic sulfide deposits. If you start seeing zálesíite, zincolivenite, azurite in float, you are in the right ground. Typical habit: aggregates, prismatic, radial. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify agardite-(nd)?+
Where is agardite-(nd) found?+
Is agardite-(nd) safe to handle?+
What rocks look like agardite-(nd)?+
What minerals are found with agardite-(nd)?+
What kind of rock does agardite-(nd) form in?+
What is agardite-(nd) used for?+
Find agardite-(nd) on the map
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