Hydroxyplumbopyrochlore is a rare lead-dominant member of the pyrochlore supergroup found in evolved alkaline pegmatites. It typically occurs as distinct, resinous octahedral crystals that are often dark brown or yellowish-brown in color. Collectors prize these for their complexity and rarity, though they require careful handling due to lead content and radioactivity.

Hardness

~5.5

Mohs

Luster

Adamantine

Streak

White

Transparency

Transparent

mineralrarePyrochlore Supergroup family

Hydroxyplumbopyrochlore

Hardness: ~5.5
Luster: Adamantine
Streak: White
Transparency: Transparent

No image

Is this hydroxyplumbopyrochlore?

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 hydroxyplumbopyrochlore with a known reference. Hydroxyplumbopyrochlore sits at Mohs ~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: white.
3
Read the luster
Hold the specimen under a strong light. Luster: adamantine.
4
Match the color range
Compare against the expected color range: pale yellow, pale brown.
5
Look at form & habit
Crystal system: cubic. Typical habit: octahedral crystals.

Often confused with

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

mineral

Pyrochlore

Mohs 5-5.5

How to tell apart: Streak differs, so Hydroxyplumbopyrochlore leaves white, Pyrochlore leaves brown; luster reads adamantine on Hydroxyplumbopyrochlore and vitreous to resinous on Pyrochlore.

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Often found alongside hydroxyplumbopyrochlore

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

All properties

Chemical formula: (Pb₁.₅□₀.₅)Nb₂O₆(OH)
Mohs hardness: ~5.5
Density: 6.474 g/cm³
Colors: Pale yellow Pale brown
Streak: White
Luster: Adamantine
Transparency: Transparent
Crystal system: Cubic
Crystal habit: Octahedral crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: From pegmatite-aplite in a peralkaline granitic complex

Where rockhounds find hydroxyplumbopyrochlore

Classic worldwide localities

Jabal Sayid peralkaline granitic complex, Arabian Shield, Saudi Arabia

Field-hunting tip

Where it forms: From pegmatite-aplite in a peralkaline granitic complex. If you start seeing quartz, microcline, biotite in float, you are in the right ground. Typical habit: octahedral crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hydroxyplumbopyrochlore?+

Mohs hardness is ~5.5. Luster: adamantine. The streak is white. Common colors include pale yellow, pale brown.

Where is hydroxyplumbopyrochlore found?+

Notable localities include Jabal Sayid peralkaline granitic complex, Arabian Shield, Saudi Arabia.

Is hydroxyplumbopyrochlore safe to handle?+

Hydroxyplumbopyrochlore contains lead. Contains lead and is radioactive; handle with care, avoid creating dust, and store away from other minerals to prevent radioactive damage to sensitive specimens.

What rocks look like hydroxyplumbopyrochlore?+

Hydroxyplumbopyrochlore is most often confused with Pyrochlore. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with hydroxyplumbopyrochlore?+

Hydroxyplumbopyrochlore commonly co-occurs with Quartz, Microcline, Biotite, Rutile, Zircon, Calcite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hydroxyplumbopyrochlore form in?+

Where it forms: From pegmatite-aplite in a peralkaline granitic complex. Working float back to the host body is the standard way to chase a fresh occurrence.

What is hydroxyplumbopyrochlore used for?+

Hydroxyplumbopyrochlore is used in collector.

Find hydroxyplumbopyrochlore on the map

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