Zaïrite is a rare bismuth-iron phosphate mineral belonging to the alunite supergroup. It is typically found as small, vibrant yellow to greenish-brown crusts or minute crystals within hydrothermal mineral assemblages.

Hardness

4-5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareWoodhouseite Group family

Zaïrite

Hardness: 4-5
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this zaïrite?

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 zaïrite with a known reference. Zaïrite sits at Mohs 4-5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Zaïrite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Zaïrite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, yellowish-green, brown.
5
Look at form & habit
Crystal system: trigonal. Typical habit: microcrystalline aggregates, crusts, or small rhombohedral crystals.

Often confused with

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

mineral

Corkite

Mohs 3.5-4

How to tell apart: Streak differs — Zaïrite leaves white, Corkite leaves yellow.

How to tell apart: Streak differs — Zaïrite leaves white, Beudantite leaves yellow.

Compare →

Often found alongside zaïrite

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

All properties

Chemical formula: BiFe₃(PO₄)₂(OH)₆
Mohs hardness: 4-5
Density: 3.55 g/cm³
Colors: Yellow Yellowish-green Brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Trigonal
Crystal habit: Microcrystalline Aggregates, Crusts, Or Small Rhombohedral Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins, Pegmatites
Typical price: $20-100 per specimen

Where rockhounds find zaïrite

Classic worldwide localities

Zaïre
France
Portugal

Field-hunting tip

Look in hydrothermal veins, pegmatites country — that is the host setting where zaïrite typically forms. If you start seeing monazite, xenotime, quartz in float, you are in the right ground. Field specimens usually show a microcrystalline aggregates, crusts, or small rhombohedral crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify zaïrite?+

Mohs hardness is 4-5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, yellowish-green, brown.

Where is zaïrite found?+

Notable localities include Zaïre; France; Portugal.

How much is zaïrite worth?+

Typical asking prices fall in the range of $20-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is zaïrite safe to handle?+

It contains toxic constituents. Contains bismuth and iron, but notably found in environments that may contain traces of other heavy metals; always wash hands after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like zaïrite?+

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

What minerals are found with zaïrite?+

Zaïrite commonly co-occurs with Monazite, Xenotime, Quartz, Hematite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does zaïrite form in?+

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

What is zaïrite used for?+

Zaïrite is used in collector.

Find zaïrite on the map

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