Švenekite is a very rare calcium arsenate mineral that typically forms as delicate, colorless tabular crystals or thin crusts in weathered arsenic-rich deposits. It is named after the mineralogist Karel Švenek and is primarily found in old mining districts where oxidation of primary arsenic minerals has occurred.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent to translucent

mineralrare

Švenekite

Hardness: ~2
Luster: Vitreous
Streak: White
Transparency: Transparent to translucent

Is this švenekite?

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 švenekite with a known reference. Švenekite 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. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: colorless, white.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals, crusts.

Often confused with

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

All properties

Chemical formula: Ca(H₂AsO₄)₂
Mohs hardness: ~2
Density: 3.16 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent to translucent
Crystal system: Triclinic
Crystal habit: Tabular crystals, crusts
Cleavage: Very good on {010}
Rarity: Rare
Uses: Collector
Host rock: A secondary mineral coating granite near a polymetallic hydrothermal vein

Where rockhounds find švenekite

Classic worldwide localities

Jáchymov, Czech Republic
Wittichen, Germany

Field-hunting tip

Where it forms: A secondary mineral coating granite near a polymetallic hydrothermal vein. If you start seeing none given in float, you are in the right ground. Typical habit: tabular crystals, crusts. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify švenekite?+

Mohs hardness is ~2. Luster: vitreous. The streak is white. Common colors include colorless, white.

Where is švenekite found?+

Notable localities include Jáchymov, Czech Republic; Wittichen, Germany.

Is švenekite safe to handle?+

Švenekite contains arsenic and calls for real care. Contains arsenic, which is toxic. Handle with care, avoid ingestion, inhalation of dust, or prolonged skin contact, and wash hands thoroughly after handling.

What rocks look like švenekite?+

Švenekite is most often confused with Pharmacolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with švenekite?+

Švenekite commonly co-occurs with None given. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does švenekite form in?+

Where it forms: A secondary mineral coating granite near a polymetallic hydrothermal vein. Working float back to the host body is the standard way to chase a fresh occurrence.

What is švenekite used for?+

Švenekite is used in collector.

Find švenekite on the map

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