Tarbuttite is a rare zinc phosphate mineral typically found in the oxidation zones of ore deposits. It is highly prized by collectors for its sharp, distinctively shaped prismatic crystals, which are most famously associated with the Broken Hill mine in Zambia.

Hardness

3.5-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Tarbuttite

Hardness: 3.5-4
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this tarbuttite?

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 tarbuttite with a known reference. Tarbuttite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Tarbuttite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Tarbuttite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white, yellowish, greenish.
5
Look at form & habit
Crystal system: triclinic. Typical habit: prismatic crystals, globular aggregates, radiating groups.

Often confused with

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

Often found alongside tarbuttite

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

All properties

Chemical formula: Zn₂(PO₄)(OH)
Mohs hardness: 3.5-4
Density: 4.1 g/cm³
Colors: Colorless White Yellowish Greenish
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Prismatic Crystals, Globular Aggregates, Radiating Groups
Cleavage: Perfect On {101}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Zinc-lead Deposits
Typical price: $50-500 depending on specimen size and clarity

Where rockhounds find tarbuttite

Classic worldwide localities

Broken Hill, Zambia
Namibia
Democratic Republic of the Congo

Field-hunting tip

Look in oxidized zones of zinc-lead deposits country — that is the host setting where tarbuttite typically forms. If you start seeing hopeite, descloizite, smithsonite in float, you are in the right ground. Field specimens usually show a prismatic crystals, globular aggregates, radiating groups habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tarbuttite?+

Mohs hardness is 3.5-4. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, yellowish, greenish.

Where is tarbuttite found?+

Notable localities include Broken Hill, Zambia; Namibia; Democratic Republic of the Congo.

How much is tarbuttite worth?+

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

Is tarbuttite safe to handle?+

It contains toxic constituents. Contains zinc and phosphorus; wash hands after handling and avoid ingestion or inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like tarbuttite?+

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

What minerals are found with tarbuttite?+

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

What kind of rock does tarbuttite form in?+

Tarbuttite typically forms in oxidized zones of zinc-lead deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is tarbuttite used for?+

Tarbuttite is used in collector.

Find tarbuttite on the map

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