Oxycalciopyrochlore is a rare member of the pyrochlore group, typically found as small, well-formed octahedral crystals in carbonatite deposits. It is identifiable by its dark brown to black coloration and submetallic to vitreous luster. Due to its radioactive content, it is primarily a specimen of interest for advanced mineral collectors and those studying complex oxide geochemistry.

Hardness

5-5.5

Mohs

Luster

Vitreous

Streak

Pale Yellow

Transparency

Translucent

mineralrarePyrochlore Group family

Oxycalciopyrochlore

Hardness: 5-5.5
Luster: Vitreous
Streak: Pale Yellow
Transparency: Translucent

Is this oxycalciopyrochlore?

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 oxycalciopyrochlore with a known reference. Oxycalciopyrochlore 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. Oxycalciopyrochlore leaves a pale yellow streak.
3
Read the luster
Hold the specimen under a strong light. Oxycalciopyrochlore typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: brown, yellowish-brown, black.
5
Look at form & habit
Crystal system: cubic. Typical habit: octahedral crystals.

Often found alongside oxycalciopyrochlore

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

All properties

Chemical formula: Ca₂Nb₂O₆O
Mohs hardness: 5-5.5
Density: 4.2-4.5 g/cm³
Colors: Brown Yellowish-brown Black
Streak: Pale Yellow
Luster: Vitreous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Octahedral Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Carbonatites
Typical price: $30-150 per specimen

Where rockhounds find oxycalciopyrochlore

Classic worldwide localities

Lueshe, DR Congo
Araxá, Brazil
Kola Peninsula, Russia

Field-hunting tip

Look in carbonatites country — that is the host setting where oxycalciopyrochlore typically forms. If you start seeing calcite, apatite, phlogopite in float, you are in the right ground. Field specimens usually show a octahedral crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify oxycalciopyrochlore?+

Mohs hardness is 5-5.5. It typically shows a vitreous luster. The streak is pale yellow. Common colors include brown, yellowish-brown, black.

Where is oxycalciopyrochlore found?+

Notable localities include Lueshe, DR Congo; Araxá, Brazil; Kola Peninsula, Russia.

How much is oxycalciopyrochlore worth?+

Typical asking prices fall in the range of $30-150 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is oxycalciopyrochlore safe to handle?+

This mineral is radioactive. Contains thorium and uranium trace elements which render it radioactive; handle with care and store in a sealed container away from living areas. Handle with care, avoid grinding or breathing dust, and store separately.

What minerals are found with oxycalciopyrochlore?+

Oxycalciopyrochlore commonly co-occurs with Calcite, Apatite, Phlogopite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does oxycalciopyrochlore form in?+

Oxycalciopyrochlore typically forms in carbonatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is oxycalciopyrochlore used for?+

Oxycalciopyrochlore is used in collector.

Find oxycalciopyrochlore on the map

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