Mambertiite is a rare bismuth molybdenum hydroxide, typically pale yellow. It is a secondary oxidation product. It was first described from Su Seinargiu, Sarroch, Cagliari, Sardinia, Italy.

Hardness

Mohs

Luster

Adamantine

Streak

White

Transparency

Transparent

mineralrare

Mambertiite

Mambertiite is a rare bismuth molybdenum hydroxide, typically pale yellow. It is a secondary oxidation product. It was first described from Su Seinargiu, Sarroch, Cagliari, Sardinia, Italy.

Hardness: 2
Luster: Adamantine
Streak: White
Transparency: Transparent

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Is this mambertiite?

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 mambertiite with a known reference. Mambertiite sits at Mohs 2, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Mambertiite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Mambertiite typically shows a adamantine luster.
4
Match the color range
Compare against the expected color range: pale yellow.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals.

Often confused with

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

mineral

Bismutite

Mohs 3

How to tell apart: Bismutite is the harder of the two (Mohs 3 vs. 2); streak differs, so Mambertiite leaves white, Bismutite leaves gray; luster reads adamantine on Mambertiite and vitreous to waxy to dull on Bismutite.

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Often found alongside mambertiite

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

All properties

Chemical formula: BiMo⁵⁺₂.₈O₈(OH)
Mohs hardness: 2
Density: 5.720 g/cm³
Colors: Pale Yellow
Streak: White
Luster: Adamantine
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Tabular Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins

Where rockhounds find mambertiite

Classic worldwide localities

Su Seinargiu, Sardinia, Italy

Field-hunting tip

Look in hydrothermal veins country, the host setting where mambertiite typically forms. If you start seeing bismutite, quartz in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify mambertiite?+

Mohs hardness is 2. It typically shows a adamantine luster. The streak is white. Common colors include pale yellow.

Where is mambertiite found?+

Notable localities include Su Seinargiu, Sardinia, Italy.

Is mambertiite safe to handle?+

It contains toxic constituents. Contains bismuth, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like mambertiite?+

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

What minerals are found with mambertiite?+

Mambertiite commonly co-occurs with Bismutite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mambertiite form in?+

Mambertiite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mambertiite used for?+

Mambertiite is used in collector.

Find mambertiite on the map

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