Brandãoite is a very rare hydrated beryllium aluminum phosphate mineral typically found in phosphate-rich pegmatites. It forms as delicate, transparent to translucent green to blue-green prismatic crystals. Due to its extreme rarity, it is highly sought after by advanced micromount collectors.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Brandãoite

Hardness: 6
Luster: Vitreous
Streak: White
Transparency: Transparent

No image

Is this brandãoite?

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 brandãoite with a known reference. Brandãoite sits at Mohs 6, 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: vitreous.
4
Match the color range
Compare against the expected color range: colorless crystals, white aggregates.
5
Look at form & habit
Crystal system: triclinic. Typical habit: prismatic crystals.

Often confused with

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

mineral

Vauxite

Mohs 3.5

How to tell apart: Brandãoite is noticeably harder (Mohs 6 vs. 3.5).

How to tell apart: Brandãoite is noticeably harder (Mohs 6 vs. 3).

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Often found alongside brandãoite

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

All properties

Chemical formula: BeAl₂(PO₄)₂(OH)₂(H₂O)₄·H₂O
Mohs hardness: 6
Density: 2.353 g/cm³
Colors: Colorless crystalsWhite aggregates
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Prismatic crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In an albite pocket in a tabular to lens-shaped granitic pegmatite with other secondary phosphates as products of montebrasite alteration

Where rockhounds find brandãoite

Classic worldwide localities

João Firmino mine, Pomarolli farm region, Divino das Laranjeiras County, Minas Gerais State, Brazil

Field-hunting tip

Where it forms: In an albite pocket in a tabular to lens-shaped granitic pegmatite with other secondary phosphates as products of montebrasite alteration. If you start seeing beryllonite, atencioite, zanazziite in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify brandãoite?+

Mohs hardness is 6. Luster: vitreous. The streak is white. Common colors include colorless crystals, white aggregates.

Where is brandãoite found?+

Notable localities include João Firmino mine, Pomarolli farm region, Divino das Laranjeiras County, Minas Gerais State, Brazil.

Is brandãoite safe to handle?+

Brandãoite contains beryllium. Wash your hands afterwards, never grind or breathe the dust, and store it apart from specimens you handle often.

What rocks look like brandãoite?+

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

What minerals are found with brandãoite?+

Brandãoite commonly co-occurs with Beryllonite, Atencioite, Zanazziite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does brandãoite form in?+

Where it forms: In an albite pocket in a tabular to lens-shaped granitic pegmatite with other secondary phosphates as products of montebrasite alteration. Working float back to the host body is the standard way to chase a fresh occurrence.

What is brandãoite used for?+

Brandãoite is used in collector.

Find brandãoite on the map

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