Brianite is an exceptionally rare phosphate mineral primarily known from iron meteorites. It typically appears as small, colorless to pale yellow equant crystals associated with other extraterrestrial minerals like farringtonite and stanfieldite.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Brianite

Hardness: 3.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this brianite?

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 brianite with a known reference. Brianite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Brianite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Brianite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: white, colorless, pale yellow.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: equant to tabular crystals.

Often confused with

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

mineral

Whitlockite

Mohs 5

How to tell apart: Whitlockite is the harder of the two (Mohs 5 vs. 3.5).

How to tell apart: Farringtonite is the harder of the two (Mohs 6-7 vs. 3.5).

Compare →

Often found alongside brianite

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

All properties

Chemical formula: Na₂CaMg(PO₄)₂
Mohs hardness: 3.5
Density: 3.48 g/cm³
Colors: White Colorless Pale Yellow
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Equant to Tabular Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Phosphate-rich Meteorites
Typical price: $500+ per specimen

Where rockhounds find brianite

Classic worldwide localities

Dayton meteorite (USA)
Allan Hills (Antarctica)

Field-hunting tip

Look in phosphate-rich meteorites country — that is the host setting where brianite typically forms. If you start seeing farringtonite, stanfieldite, schreibersite in float, you are in the right ground. Field specimens usually show a equant to tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify brianite?+

Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless, pale yellow.

Where is brianite found?+

Notable localities include Dayton meteorite (USA); Allan Hills (Antarctica).

How much is brianite worth?+

Typical asking prices fall in the range of $500+ per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like brianite?+

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

What minerals are found with brianite?+

Brianite commonly co-occurs with Farringtonite, Stanfieldite, Schreibersite, Troilite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does brianite form in?+

Brianite typically forms in phosphate-rich meteorites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is brianite used for?+

Brianite is used in collector.

Find brianite on the map

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