Attikaite is an extremely rare arsenate mineral that occurs as delicate, bright green acicular sprays. It is primarily known from the historic ancient slag dumps of the Lavrion district in Greece. Due to its fragility and rarity, it is highly sought after by advanced micro-mineral collectors.

Hardness

2-2.5

Mohs

Luster

Vitreous

Streak

Very pale blue

Transparency

Transparent

mineralrare

Attikaite

Hardness: 2-2.5
Luster: Vitreous
Streak: Very pale blue
Transparency: Transparent

Is this attikaite?

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 attikaite with a known reference. Attikaite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: very pale blue.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: light blue, greenish blue.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: encrustations.

Often confused with

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

mineral

Conichalcite

Mohs 4.5

How to tell apart: Conichalcite is the harder of the two (Mohs 4.5 vs. 2-2.5); streak differs, so Attikaite leaves very pale blue, Conichalcite leaves green.

How to tell apart: Austinite is the harder of the two (Mohs 4-4.5 vs. 2-2.5); streak differs, so Attikaite leaves very pale blue, Austinite leaves white; luster reads vitreous on Attikaite and subadamantine to silky in aggregates on Austinite.

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Often found alongside attikaite

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

All properties

Chemical formula: Ca₃Cu₂Al₂(AsO₄)₄(OH)₄·2H₂O
Mohs hardness: 2-2.5
Density: 3.2 g/cm³
Colors: Light blue Greenish blue
Streak: Very pale blue
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Encrustations
Cleavage: Perfect on {001}
Rarity: Rare
Uses: Collector
Host rock: In the oxidized portions of polymetallic sulfide-quartz veins

Where rockhounds find attikaite

Classic worldwide localities

Christiana no. 132 mine, Kamareza, Laurion District, Attiki Prefecture (Attika), Greece

Field-hunting tip

Where it forms: In the oxidized portions of polymetallic sulfide-quartz veins. If you start seeing arsenocrandallite, arsenogoyazite, conichalcite in float, you are in the right ground. Typical habit: encrustations. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify attikaite?+

Mohs hardness is 2-2.5. Luster: vitreous. The streak is very pale blue. Common colors include light blue, greenish blue.

Where is attikaite found?+

Notable localities include Christiana no. 132 mine, Kamareza, Laurion District, Attiki Prefecture (Attika), Greece.

Is attikaite safe to handle?+

Attikaite contains arsenic and copper and calls for real care. Contains arsenic, which is toxic; always wash hands thoroughly after handling specimens and avoid inhaling any dust.

What rocks look like attikaite?+

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

What minerals are found with attikaite?+

Attikaite commonly co-occurs with Arsenocrandallite, Arsenogoyazite, Conichalcite, Olivenite, Philipsbornite, Azurite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does attikaite form in?+

Where it forms: In the oxidized portions of polymetallic sulfide-quartz veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is attikaite used for?+

Attikaite is used in collector.

Find attikaite on the map

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