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, 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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