Hydropyrochlore is a rare member of the pyrochlore group characterized by significant vacancy in the A-site of its crystal structure and high water content. It typically forms sharp, lustrous octahedral crystals in alkaline igneous environments like carbonatites. Due to its radioactive nature, it is primarily a target for advanced systematic mineral collectors.
Is this hydropyrochlore?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch hydropyrochlore with a known reference. Hydropyrochlore sits at Mohs 4-4.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to resinous.
- 4Match the color rangeCompare against the expected color range: greenish.
- 5Look at form & habitCrystal system: cubic. Typical habit: octahedral.
Often confused with
Hydropyrochlore vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside hydropyrochlore
Minerals reported to co-occur with hydropyrochlore. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (H₂O,□)₂Nb₂(O,OH)₆(H₂O)
- Mohs hardness
- 4-4.5
- Density
- 3.40-3.48 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous to resinous
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Octahedral
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In alluvial deposits and residual soils from a carbonatite deposit, formed from pyrochlore by the leaching of Na, Ca, and F in waters rich in K ions
Where rockhounds find hydropyrochlore
Classic worldwide localities
- Lueshe carbonatite, 150 km north of Goma, Kivu Province, Congo (Zaire)
Field-hunting tip
Where it forms: In alluvial deposits and residual soils from a carbonatite deposit, formed from pyrochlore by the leaching of Na, Ca, and F in waters rich in K ions. If you start seeing na-ca pyrochlores, lueshite, columbite in float, you are in the right ground. Typical habit: octahedral. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hydropyrochlore?+
Where is hydropyrochlore found?+
Is hydropyrochlore safe to handle?+
What rocks look like hydropyrochlore?+
What minerals are found with hydropyrochlore?+
What kind of rock does hydropyrochlore form in?+
What is hydropyrochlore used for?+
Find hydropyrochlore on the map
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