Birchite is a very rare secondary cadmium copper sulfate mineral found in oxidized base metal deposits. It typically occurs as tiny, thin tabular crystals associated with lead and copper minerals in arid climates. Due to its scarcity and delicate nature, it is primarily sought after by advanced systematic mineral collectors.

Hardness

3.5-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrare

Birchite

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

Is this birchite?

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 birchite with a known reference. Birchite 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. 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: pale blue.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: aggregates, prismatic.

Often confused with

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

mineral

Serpierite

Mohs 3.5-4

How to tell apart: Streak differs, so Birchite leaves white, Serpierite leaves greenish white.

How to tell apart: Streak differs, so Birchite leaves white, Posnjakite leaves pale blue.

Compare →

Often found alongside birchite

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

All properties

Chemical formula: Cd₂Cu₂(PO₄)₂SO₄·5H₂O
Mohs hardness: 3.5-4
Density: 3.61 g/cm³
Colors: Pale blue
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Aggregates, prismatic
Cleavage: None observed
Rarity: Rare
Uses: Collector
Host rock: Late-stage supergene mineral formed as part of a suite of secondary phosphate minerals under low-temperature conditions

Where rockhounds find birchite

Classic worldwide localities

Block 14 Opencut, Broken Hill, New South Wales, Australia

Field-hunting tip

Where it forms: Late-stage supergene mineral formed as part of a suite of secondary phosphate minerals under low-temperature conditions. If you start seeing hinsdalite-plumbogummite, cerussite, anglesite in float, you are in the right ground. Typical habit: aggregates, prismatic. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify birchite?+

Mohs hardness is 3.5-4. Luster: vitreous. The streak is white. Common colors include pale blue.

Where is birchite found?+

Notable localities include Block 14 Opencut, Broken Hill, New South Wales, Australia.

Is birchite safe to handle?+

Birchite contains cadmium and copper and calls for real care. Contains cadmium and copper, both of which are heavy metals; avoid inhalation of dust and wash hands thoroughly after handling.

What rocks look like birchite?+

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

What minerals are found with birchite?+

Birchite commonly co-occurs with Hinsdalite-plumbogummite, Cerussite, Anglesite, Pyromorphite, Libethenite, Sampleite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does birchite form in?+

Where it forms: Late-stage supergene mineral formed as part of a suite of secondary phosphate minerals under low-temperature conditions. Working float back to the host body is the standard way to chase a fresh occurrence.

What is birchite used for?+

Birchite is used in collector.

Find birchite on the map

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