Zdenĕkite is a rare sodium lead copper arsenate that forms turquoise-blue tabular crystals. It was approved as a distinct mineral species in 1992. It was first described from Cap Garonne mine, near le Pradet, Var, France.

Hardness

Mohs

Luster

Vitreous

Streak

Pale Blue

Transparency

Translucent

mineralrare

Zdenĕkite

Hardness: 2
Luster: Vitreous
Streak: Pale Blue
Transparency: Translucent

Is this zdenĕkite?

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 zdenĕkite with a known reference. Zdenĕkite sits at Mohs 2, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Zdenĕkite leaves a pale blue streak.
3
Read the luster
Hold the specimen under a strong light. Zdenĕkite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: turquoise-blue.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: tabular crystals.

Often confused with

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

mineral

Woodwardite

Mohs 1.5-2.5

How to tell apart: Streak differs, so Zdenĕkite leaves pale blue, Woodwardite leaves white; luster reads vitreous on Zdenĕkite and pearly on Woodwardite.

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

Compare →

Often found alongside zdenĕkite

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

All properties

Chemical formula: NaPbCu₅(AsO₄)₄Cl·5H₂O
Mohs hardness: 2
Density: 4.1 g/cm³
Colors: Turquoise-blue
Streak: Pale Blue
Luster: Vitreous
Transparency: Translucent
Crystal system: Tetragonal
Crystal habit: Tabular Crystals
Cleavage: On {001}, Perfect
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins

Where rockhounds find zdenĕkite

Classic worldwide localities

Cap Garonne mine, Var, France

Field-hunting tip

Look in hydrothermal veins country, the host setting where zdenĕkite typically forms. If you start seeing gordaite, gymnite, gypsum in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify zdenĕkite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is pale blue. Common colors include turquoise-blue.

Where is zdenĕkite found?+

Notable localities include Cap Garonne mine, Var, France.

Is zdenĕkite safe to handle?+

It contains toxic constituents. Contains arsenic and lead, which are toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like zdenĕkite?+

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

What minerals are found with zdenĕkite?+

Zdenĕkite commonly co-occurs with gordaite, gymnite, gypsum. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does zdenĕkite form in?+

Zdenĕkite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is zdenĕkite used for?+

Zdenĕkite is used in collector.

Find zdenĕkite on the map

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