Hydroxycalciopyrochlore is a rare member of the pyrochlore group often found in alkaline igneous environments like carbonatites. It typically occurs as small, well-formed octahedral crystals that are often radioactive due to trace elements like uranium and thorium.

Hardness

5-5.5

Mohs

Luster

Vitreous

Streak

Light Yellow

Transparency

Translucent

mineralrarePyrochlore Group family

Hydroxycalciopyrochlore

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

No image

Is this hydroxycalciopyrochlore?

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

Often found alongside hydroxycalciopyrochlore

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

All properties

Chemical formula: (Ca,Na,U)₂(Nb,Ti,Ta)₂(O,OH)₇(OH,F)
Mohs hardness: 5-5.5
Density: 4.2-6.4 g/cm³
Colors: Yellow Brown Reddish-brown
Streak: Light Yellow
Luster: Vitreous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Octahedral Crystals
Cleavage: None
Rarity: Rare
Uses: Collector, Scientific Research
Host rock: Carbonatites
Typical price: $50-500 depending on crystal size and quality

Where rockhounds find hydroxycalciopyrochlore

Classic worldwide localities

Fen Complex, Norway
Kola Peninsula, Russia
Oka Carbonatite, Canada

Field-hunting tip

Look in carbonatites country — that is the host setting where hydroxycalciopyrochlore typically forms. If you start seeing calcite, apatite, biotite 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 hydroxycalciopyrochlore?+

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

Where is hydroxycalciopyrochlore found?+

Notable localities include Fen Complex, Norway; Kola Peninsula, Russia; Oka Carbonatite, Canada.

How much is hydroxycalciopyrochlore worth?+

Typical asking prices fall in the range of $50-500 depending on crystal size and quality. Quality, size, and provenance can move individual specimens well outside that range.

Is hydroxycalciopyrochlore safe to handle?+

This mineral is radioactive. Contains uranium and thorium; store in a shielded container and avoid inhalation of dust when handling samples. Handle with care, avoid grinding or breathing dust, and store separately.

What minerals are found with hydroxycalciopyrochlore?+

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

What kind of rock does hydroxycalciopyrochlore form in?+

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

What is hydroxycalciopyrochlore used for?+

Hydroxycalciopyrochlore is used in collector, scientific research.

Find hydroxycalciopyrochlore on the map

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