Brugnatellite is a rare layered double hydroxide mineral typically found as soft, platy, or micaceous aggregates. It is most commonly identified in serpentinite rocks where it forms alongside other magnesium-rich minerals in low-temperature alteration zones.

Hardness

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineralrareHydrotalcite Group family

Brugnatellite

Hardness: 2
Luster: Pearly
Streak: White
Transparency: Translucent

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Is this brugnatellite?

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 brugnatellite with a known reference. Brugnatellite 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. Brugnatellite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Brugnatellite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: pale pink, pale brownish, pale yellow.
5
Look at form & habit
Crystal system: trigonal. Typical habit: platy or foliated aggregates, crusts.

Often confused with

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

How to tell apart: Luster reads pearly on Brugnatellite and waxy on Stichtite.

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Often found alongside brugnatellite

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

All properties

Chemical formula: Mg₆Fe³⁺(CO₃)(OH)₁₃·4H₂O
Mohs hardness: 2
Density: 2.12 g/cm³
Colors: Pale Pink Pale Brownish Pale Yellow
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Trigonal
Crystal habit: Platy or Foliated Aggregates, Crusts
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector
Host rock: Serpentinite and Alkaline Igneous Rocks
Typical price: $20-100 per specimen depending on size

Where rockhounds find brugnatellite

Classic worldwide localities

Brugnato, Liguria, Italy
Khibiny Massif, Russia
Mont Saint-Hilaire, Canada

Field-hunting tip

Look in serpentinite and alkaline igneous rocks country, the host setting where brugnatellite typically forms. If you start seeing aragonite, calcite, brucite in float, you are in the right ground. Field specimens usually show a platy or foliated aggregates, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify brugnatellite?+

Mohs hardness is 2. It typically shows a pearly luster. The streak is white. Common colors include pale pink, pale brownish, pale yellow.

Where is brugnatellite found?+

Notable localities include Brugnato, Liguria, Italy; Khibiny Massif, Russia; Mont Saint-Hilaire, Canada.

How much is brugnatellite worth?+

Typical asking prices fall in the range of $20-100 per specimen depending on size. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like brugnatellite?+

Brugnatellite is most often confused with Hydrotalcite, Pyroaurite, Stichtite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with brugnatellite?+

Brugnatellite commonly co-occurs with Aragonite, Calcite, Brucite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does brugnatellite form in?+

Brugnatellite typically forms in serpentinite and alkaline igneous rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is brugnatellite used for?+

Brugnatellite is used in collector.

Find brugnatellite on the map

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