Fuettererite is a rare lead-copper tellurite mineral discovered in the oxidized zones of Mexican ore deposits. It typically forms as delicate, pale green to yellow-green tabular crystals and is highly prized by advanced mineral collectors for its chemical complexity and scarcity.

Hardness

2-3

Mohs

Luster

Adamantine

Streak

Pale bluish green

Transparency

Transparent

mineralrare

Fuettererite

Hardness: 2-3
Luster: Adamantine
Streak: Pale bluish green
Transparency: Transparent

Is this fuettererite?

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 fuettererite with a known reference. Fuettererite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: pale bluish green.
3
Read the luster
Hold the specimen under a strong light. Luster: adamantine.
4
Match the color range
Compare against the expected color range: bluish green.
5
Look at form & habit
Crystal system: trigonal. Typical habit: tabular crystals, subparallel aggregates.

Often confused with

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

mineral

Emmonsite

Mohs ~5

How to tell apart: Emmonsite is the harder of the two (Mohs ~5 vs. 2-3); luster reads adamantine on Fuettererite and vitreous on Emmonsite.

How to tell apart: Luster reads adamantine on Fuettererite and pearly to dull on Quetzalcoatlite.

Compare →

Often found alongside fuettererite

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

All properties

Chemical formula: Pb₃Cu₆TeO₆(OH)₇Cl₅
Mohs hardness: 2-3
Density: 5.552 g/cm³
Colors: Bluish green
Streak: Pale bluish green
Luster: Adamantine
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Tabular crystals, subparallel aggregates
Cleavage: Perfect on {001}
Rarity: Rare
Uses: Collector
Host rock: A secondary phase formed by partial oxidation of tellurides, chalcopyrite and galena in quartz veins

Where rockhounds find fuettererite

Classic worldwide localities

NE2 vein and the Bird Nest drift, Otto Mountain, near Baker, California, USA

Field-hunting tip

Where it forms: A secondary phase formed by partial oxidation of tellurides, chalcopyrite and galena in quartz veins. If you start seeing br-rich chlorargyrite, iodargyrite, telluroperite in float, you are in the right ground. Typical habit: tabular crystals, subparallel aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify fuettererite?+

Mohs hardness is 2-3. Luster: adamantine. The streak is pale bluish green. Common colors include bluish green.

Where is fuettererite found?+

Notable localities include NE2 vein and the Bird Nest drift, Otto Mountain, near Baker, California, USA.

Is fuettererite safe to handle?+

Fuettererite contains copper and lead. Contains lead (Pb) and tellurium compounds; handle with care, wash hands thoroughly after contact, and do not inhale dust.

What rocks look like fuettererite?+

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

What minerals are found with fuettererite?+

Fuettererite commonly co-occurs with Br-rich chlorargyrite, Iodargyrite, Telluroperite, Paratacamite, Anglesite, Anatacamite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does fuettererite form in?+

Where it forms: A secondary phase formed by partial oxidation of tellurides, chalcopyrite and galena in quartz veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is fuettererite used for?+

Fuettererite is used in collector.

Find fuettererite on the map

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