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 — that is 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.