Pyrochlore is the niobium member of the pyrochlore supergroup and the main ore of niobium: the three largest niobium producers, led by the CBMM mine near Araxá, Brazil, all mine pyrochlore deposits. It usually forms well-shaped octahedra, brown to reddish brown with a vitreous to resinous luster, and it is characteristic of carbonatites and of pegmatites in alkalic rocks. It is commonly metamict, its structure damaged by radiation from included uranium and thorium. The name comes from the Greek for fire and green, the color it usually turns when heated.

Hardness

5-5.5

Mohs

Luster

Vitreous to resinous

Streak

Brown

Transparency

Translucent

mineralPyrochlore Supergroup family

Pyrochlore

Hardness: 5-5.5
Luster: Vitreous to resinous
Streak: Brown
Transparency: Translucent

Is this pyrochlore?

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 pyrochlore with a known reference. Pyrochlore sits at Mohs 5-5.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: brown.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous to resinous.
4
Match the color range
Compare against the expected color range: black, brown, chocolate brown, reddish brown, amber orange, red orange.
5
Look at form & habit
Crystal system: cubic. Typical habit: octahedral crystals; granular, massive.

Often found alongside pyrochlore

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

All properties

Chemical formula: (Na,Ca)₂Nb₂O₆(OH,F)
Mohs hardness: 5-5.5
Density: 4.33 g/cm³
Colors: Black BrownChocolate brownReddish brownAmber orangeRed orange
Streak: Brown
Luster: Vitreous to resinous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Octahedral crystals; granular, massive
Cleavage: On {111}, may be a parting
Uses: Ore of niobium
Host rock: Carbonatites; pegmatites in nepheline syenites and other alkalic rocks; granite pegmatites and greisens

Where rockhounds find pyrochlore

Classic worldwide localities

Fredriksvärn and Larvik, Norway (type locality)
Araxá, Minas Gerais, Brazil
Oka, Quebec, Canada
Panda Hill, Mbeya, Tanzania
Lovozero massif, Kola Peninsula, Russia

Field-hunting tip

Where it forms: Carbonatites; pegmatites in nepheline syenites and other alkalic rocks; granite pegmatites and greisens. If you start seeing zircon, aegirine, apatite in float, you are in the right ground. Typical habit: octahedral crystals; granular, massive. Train your eye for that shape before scanning the outcrop.

More pyrochlore photos

Common questions

How do you identify pyrochlore?+

Mohs hardness is 5-5.5. Luster: vitreous to resinous. The streak is brown. Common colors include black, brown, chocolate brown, reddish brown.

Where is pyrochlore found?+

Notable localities include Fredriksvärn and Larvik, Norway (type locality); Araxá, Minas Gerais, Brazil; Oka, Quebec, Canada; Panda Hill, Mbeya, Tanzania; Lovozero massif, Kola Peninsula, Russia.

Is pyrochlore safe to handle?+

Pyrochlore contains trace uranium or thorium. May be radioactive. It is commonly metamict, its structure damaged by radiation from included uranium and thorium.

What minerals are found with pyrochlore?+

Pyrochlore commonly co-occurs with Zircon, Aegirine, Apatite, Perovskite, Columbite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does pyrochlore form in?+

Where it forms: Carbonatites; pegmatites in nepheline syenites and other alkalic rocks; granite pegmatites and greisens. Working float back to the host body is the standard way to chase a fresh occurrence.

What is pyrochlore used for?+

Pyrochlore is used in ore of niobium.

Find pyrochlore on the map

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