Gaitite is a rare arsenate mineral that forms as thin, bladed crystals often arranged in delicate radiating clusters. It is almost exclusively found in the unique oxidation zone of the Tsumeb Mine in Namibia. Its distinct crystal habit and association with other rare secondary arsenates make it a prize for advanced mineral collectors.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Semitransparent

mineralrare

Gaitite

Hardness: ~5
Luster: Vitreous
Streak: White
Transparency: Semitransparent

Is this gaitite?

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 gaitite with a known reference. Gaitite sits at Mohs ~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: 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: encrustations, granular, spherical.

Often confused with

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

mineral

Villyaellenite

Mohs ~4

How to tell apart: Gaitite is noticeably harder (Mohs ~5 vs. ~4).

Often found alongside gaitite

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

All properties

Chemical formula: Ca₂Zn(AsO₄)₂·2H₂O
Mohs hardness: ~5
Density: 3.81 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Semitransparent
Crystal system: Triclinic
Crystal habit: Encrustations, granular, spherical
Cleavage: {010}, {001}, and {011}, probable, equally good
Rarity: Rare
Uses: Collector
Host rock: A very rare mineral from a deep oxidized zone in a dolostone-hosted, hydrothermal, polymetallic ore deposit

Where rockhounds find gaitite

Classic worldwide localities

Tsumeb, Namibia

Field-hunting tip

Where it forms: A very rare mineral from a deep oxidized zone in a dolostone-hosted, hydrothermal, polymetallic ore deposit. If you start seeing talmessite, prosperite, adamite in float, you are in the right ground. Typical habit: encrustations, granular, spherical. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify gaitite?+

Mohs hardness is ~5. Luster: vitreous. The streak is white. Common colors include colorless, white.

Where is gaitite found?+

Notable localities include Tsumeb, Namibia.

Is gaitite safe to handle?+

Gaitite contains arsenic and calls for real care. Contains arsenic, a toxic element. Handle with care, avoid creating dust, and wash hands thoroughly after handling specimens.

What rocks look like gaitite?+

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

What minerals are found with gaitite?+

Gaitite commonly co-occurs with Talmessite, Prosperite, Adamite, Conichalcite, Austinite, Barite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does gaitite form in?+

Where it forms: A very rare mineral from a deep oxidized zone in a dolostone-hosted, hydrothermal, polymetallic ore deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is gaitite used for?+

Gaitite is used in collector.

Find gaitite on the map

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