Biraite-(Ce) is an extremely rare cerium-iron carbonate-silicate typically found in alkaline rock formations. It usually occurs as small, tabular, yellowish-brown crystals and is primarily a target for advanced systematic mineral collectors due to its limited type locality in the Russian Far East.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrare

Biraite-(Ce)

Hardness: 5
Luster: Vitreous
Streak: White
Transparency: Translucent

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Is this biraite-(ce)?

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 biraite-(ce) with a known reference. Biraite-(Ce) sits at Mohs 5, 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: brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: irregular grains.

Often confused with

Biraite-(Ce) vs. its common look-alikes, and how to tell them apart in the field.

How to tell apart: Streak differs, so Biraite-(Ce) leaves white, Allanite leaves gray; luster reads vitreous on Biraite-(Ce) and submetallic on Allanite.

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Often found alongside biraite-(ce)

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

All properties

Chemical formula: Ce₂FeSi₂O₇(CO₃)
Mohs hardness: 5
Density: 4.76 g/cm³
Colors: Brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Irregular grains
Rarity: Rare
Uses: Collector
Host rock: In a vein that cuts fenite fragments in a carbonatite

Where rockhounds find biraite-(ce)

Classic worldwide localities

Biraia cabonatite dike, 145-150 km east of Bodaibo, Northern Irkutsk district, Siberia, Russia

Field-hunting tip

Where it forms: In a vein that cuts fenite fragments in a carbonatite. If you start seeing cordylite-, aragonite, dolomite in float, you are in the right ground. Typical habit: irregular grains. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify biraite-(ce)?+

Mohs hardness is 5. Luster: vitreous. The streak is white. Common colors include brown.

Where is biraite-(ce) found?+

Notable localities include Biraia cabonatite dike, 145-150 km east of Bodaibo, Northern Irkutsk district, Siberia, Russia.

What rocks look like biraite-(ce)?+

Biraite-(Ce) is most often confused with Bastnäsite, Allanite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with biraite-(ce)?+

Biraite-(Ce) commonly co-occurs with Cordylite-, Aragonite, Dolomite, Ancylite-, Hydroxylbastnäsite-, Daqingshanite-. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does biraite-(ce) form in?+

Where it forms: In a vein that cuts fenite fragments in a carbonatite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is biraite-(ce) used for?+

Biraite-(Ce) is used in collector.

Find biraite-(ce) on the map

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