Davidlloydite is an extremely rare zinc arsenate mineral that occurs as small, delicate tabular crystals. It is primarily found in the Tsumeb Mine in Namibia, typically associated with other secondary arsenic and zinc minerals in the oxidation zone of ore deposits.

Hardness

3-4

Mohs

Luster

Vitreous to opalescent

Streak

White

Transparency

Transparent

mineralrareHopeite Group family

Davidlloydite

Hardness: 3-4
Luster: Vitreous to opalescent
Streak: White
Transparency: Transparent

No image

Is this davidlloydite?

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

Often confused with

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

Often found alongside davidlloydite

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

All properties

Chemical formula: Zn₃(AsO₄)₂·4H₂O
Mohs hardness: 3-4
Density: 3.661 g/cm³
Colors: Colorless
Streak: White
Luster: Vitreous to opalescent
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Tabular crystals
Cleavage: Distinct on {010}
Rarity: Rare
Uses: Collector
Host rock: Secondary in the oxidation zone of a Cu-Pb-Zn mineral deposit

Where rockhounds find davidlloydite

Classic worldwide localities

Tsumeb mine, Otjikoto (Oshikoto) region, Namibia

Field-hunting tip

Where it forms: Secondary in the oxidation zone of a Cu-Pb-Zn mineral deposit. If you start seeing calcioandyrobertsite, stranskiite, geminite in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify davidlloydite?+

Mohs hardness is 3-4. Luster: vitreous to opalescent. The streak is white. Common colors include colorless.

Where is davidlloydite found?+

Notable localities include Tsumeb mine, Otjikoto (Oshikoto) region, Namibia.

Is davidlloydite safe to handle?+

Davidlloydite contains arsenic and calls for real care. Contains arsenic, a toxic element. Handle with care, wash hands after touching, and avoid inhaling dust.

What rocks look like davidlloydite?+

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

What minerals are found with davidlloydite?+

Davidlloydite commonly co-occurs with Calcioandyrobertsite, Stranskiite, Geminite, Adamite-olivenite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does davidlloydite form in?+

Where it forms: Secondary in the oxidation zone of a Cu-Pb-Zn mineral deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is davidlloydite used for?+

Davidlloydite is used in collector.

Find davidlloydite on the map

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