Osarizawaite is a rare lead-copper aluminum sulfate mineral typically found as secondary crusts or powdery coatings in oxidized ore deposits. It is most easily identified by its distinct yellowish-green color and association with other secondary lead and copper minerals.

Hardness

3.5

Mohs

Luster

Dull

Streak

Yellowish-white

Transparency

Opaque

mineralrareAlunite Supergroup family

Osarizawaite

Hardness: 3.5
Luster: Dull
Streak: Yellowish-white
Transparency: Opaque

Is this osarizawaite?

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 osarizawaite with a known reference. Osarizawaite 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. Osarizawaite leaves a yellowish-white streak.
3
Read the luster
Hold the specimen under a strong light. Osarizawaite typically shows a dull luster.
4
Match the color range
Compare against the expected color range: yellow, greenish-yellow.
5
Look at form & habit
Crystal system: trigonal. Typical habit: massive, powdery, or as crusts.

Often confused with

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

mineral

Jarosite

Mohs 2.5-3.5

How to tell apart: Streak differs — Osarizawaite leaves yellowish-white, Jarosite leaves yellow; luster reads dull on Osarizawaite and vitreous on Jarosite.

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Often found alongside osarizawaite

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

All properties

Chemical formula: PbCuAl₂(SO₄)₂(OH)₆
Mohs hardness: 3.5
Density: 4.15 g/cm³
Colors: Yellow Greenish-yellow
Streak: Yellowish-white
Luster: Dull
Transparency: Opaque
Crystal system: Trigonal
Crystal habit: Massive, Powdery, Or as Crusts
Cleavage: None Observed
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Lead-copper Hydrothermal Deposits
Typical price: $20-100 for small thumbnail or micro specimens

Where rockhounds find osarizawaite

Classic worldwide localities

Osarizawa mine, Akita Prefecture, Japan
Tsumeb, Namibia
Chuquicamata, Chile

Field-hunting tip

Look in oxidized zones of lead-copper hydrothermal deposits country — that is the host setting where osarizawaite typically forms. If you start seeing anglesite, cerussite, malachite in float, you are in the right ground. Field specimens usually show a massive, powdery, or as crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify osarizawaite?+

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

Where is osarizawaite found?+

Notable localities include Osarizawa mine, Akita Prefecture, Japan; Tsumeb, Namibia; Chuquicamata, Chile.

How much is osarizawaite worth?+

Typical asking prices fall in the range of $20-100 for small thumbnail or micro specimens. Quality, size, and provenance can move individual specimens well outside that range.

Is osarizawaite safe to handle?+

It contains toxic constituents. Contains lead and copper, which are toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust when breaking specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like osarizawaite?+

Osarizawaite is most often confused with Jarosite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with osarizawaite?+

Osarizawaite commonly co-occurs with Anglesite, Cerussite, Malachite, Linarite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does osarizawaite form in?+

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

What is osarizawaite used for?+

Osarizawaite is used in collector.

Find osarizawaite on the map

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