Arsenohopeite is a rare hydrated zinc arsenate found in the oxidized zones of base metal deposits. It typically forms as small, colorless to white tabular crystals that are visually indistinguishable from its phosphate analog, Hopeite, without chemical analysis.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareHopeite Group family

Arsenohopeite

Hardness: 3.5
Luster: Vitreous
Streak: White
Transparency: Transparent

No image

Is this arsenohopeite?

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 arsenohopeite with a known reference. Arsenohopeite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Arsenohopeite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Arsenohopeite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: tabular crystals.

Often confused with

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

Often found alongside arsenohopeite

Minerals reported to co-occur with arsenohopeite. 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: 3.5
Density: 3.31 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Tabular Crystals
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zinc Deposits
Typical price: $50-500 thumbnail

Where rockhounds find arsenohopeite

Classic worldwide localities

Broken Hill, Zambia
Tsumeb, Namibia

Field-hunting tip

Look in oxidized zinc deposits country — that is the host setting where arsenohopeite typically forms. If you start seeing hopeite, smithsonite, hemimorphite 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 arsenohopeite?+

Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white.

Where is arsenohopeite found?+

Notable localities include Broken Hill, Zambia; Tsumeb, Namibia.

How much is arsenohopeite worth?+

Typical asking prices fall in the range of $50-500 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

Is arsenohopeite safe to handle?+

It contains toxic constituents. Contains arsenic, a toxic element. Handle with care, avoid inhalation of dust, and wash hands thoroughly after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like arsenohopeite?+

Arsenohopeite 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 arsenohopeite?+

Arsenohopeite commonly co-occurs with Hopeite, Smithsonite, Hemimorphite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does arsenohopeite form in?+

Arsenohopeite typically forms in oxidized zinc deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is arsenohopeite used for?+

Arsenohopeite is used in collector.

Find arsenohopeite on the map

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