Bideauxite is an extremely rare lead-silver halide mineral found in the oxidized zones of certain ore deposits. It typically occurs as small, sharp octahedral or cubic crystals that exhibit a distinct adamantine luster.

Hardness

Mohs

Luster

Adamantine, dull after exposure to light

Streak

White

Transparency

Transparent

mineralrare

Bideauxite

Hardness: 3
Luster: Adamantine, dull after exposure to light
Streak: White
Transparency: Transparent

No image

Is this bideauxite?

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 bideauxite with a known reference. Bideauxite sits at Mohs 3, 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: adamantine, dull after exposure to light.
4
Match the color range
Compare against the expected color range: colorless, pale lavender.
5
Look at form & habit
Crystal system: cubic. Typical habit: small octahedral to cubic crystals.

Often confused with

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

Often found alongside bideauxite

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

All properties

Chemical formula: AgPb₂F₂Cl₃
Mohs hardness: 3
Density: 6.274 g/cm³
Colors: ColorlessPale lavender
Streak: White
Luster: Adamantine, dull after exposure to light
Transparency: Transparent
Crystal system: Cubic
Crystal habit: Small octahedral to cubic crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Rarely enclosing and replacing boleite, with other oxidized Pb and Cl minerals, from an oxidized base-metal mineral deposit (Tiger, Arizona, USA)

Where rockhounds find bideauxite

Classic worldwide localities

Mammoth-St. Anthony mine, Tiger, Pinal Co., Arizona, USA
A prospect about 20 km east of Iquique, Tarapacá, Chile

Field-hunting tip

Where it forms: Rarely enclosing and replacing boleite, with other oxidized Pb and Cl minerals, from an oxidized base-metal mineral deposit (Tiger, Arizona, USA). If you start seeing boleite, diaboleite, matlockite in float, you are in the right ground. Typical habit: small octahedral to cubic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify bideauxite?+

Mohs hardness is 3. Luster: adamantine, dull after exposure to light. The streak is white. Common colors include colorless, pale lavender.

Where is bideauxite found?+

Notable localities include Mammoth-St. Anthony mine, Tiger, Pinal Co., Arizona, USA; A prospect about 20 km east of Iquique, Tarapacá, Chile.

Is bideauxite safe to handle?+

Bideauxite contains lead. Contains lead, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling specimens.

What rocks look like bideauxite?+

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

What minerals are found with bideauxite?+

Bideauxite commonly co-occurs with Boleite, Diaboleite, Matlockite, Leadhillite, Anglesite, Cerussite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does bideauxite form in?+

Where it forms: Rarely enclosing and replacing boleite, with other oxidized Pb and Cl minerals, from an oxidized base-metal mineral deposit (Tiger, Arizona, USA). Working float back to the host body is the standard way to chase a fresh occurrence.

What is bideauxite used for?+

Bideauxite is used in collector.

Find bideauxite on the map

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