Hydrokenomicrolite is a rare member of the pyrochlore supergroup characterized by high water content and a vacant A-site in its crystal structure. Collectors typically seek out its distinct octahedral crystals found within complex granitic pegmatites.

Hardness

4.5-5

Mohs

Luster

Adamantine to resinous

Streak

White

Transparency

Translucent

mineralrarePyrochlore Supergroup family

Hydrokenomicrolite

Hardness: 4.5-5
Luster: Adamantine to resinous
Streak: White
Transparency: Translucent

Is this hydrokenomicrolite?

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 hydrokenomicrolite with a known reference. Hydrokenomicrolite sits at Mohs 4.5-5, 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 to resinous.
4
Match the color range
Compare against the expected color range: pinkish brown.
5
Look at form & habit
Crystal system: cubic. Typical habit: octahedral crystals.

Often confused with

Hydrokenomicrolite 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 Hydrokenomicrolite leaves white, Pyrochlore leaves brown; luster reads adamantine to resinous on Hydrokenomicrolite and vitreous to resinous on Pyrochlore.

Compare →

Often found alongside hydrokenomicrolite

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

All properties

Chemical formula: □₂Ta₂O₆(H₂O)
Mohs hardness: 4.5-5
Density: 6.666 g/cm³
Colors: Pinkish brown
Streak: White
Luster: Adamantine to resinous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Octahedral crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: An accessory mineral in the heavy mineral concentrate from a zoned granitic pegmatite

Where rockhounds find hydrokenomicrolite

Classic worldwide localities

Volta Grande pegmatite, Sn-Ta-rich São João del Rei Pegmatite Province, Nazareno, Minas Gerais, Brazil

Field-hunting tip

Where it forms: An accessory mineral in the heavy mineral concentrate from a zoned granitic pegmatite. If you start seeing microcline, albite, quartz 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 hydrokenomicrolite?+

Mohs hardness is 4.5-5. Luster: adamantine to resinous. The streak is white. Common colors include pinkish brown.

Where is hydrokenomicrolite found?+

Notable localities include Volta Grande pegmatite, Sn-Ta-rich São João del Rei Pegmatite Province, Nazareno, Minas Gerais, Brazil.

What rocks look like hydrokenomicrolite?+

Hydrokenomicrolite 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 hydrokenomicrolite?+

Hydrokenomicrolite commonly co-occurs with Microcline, Albite, Quartz, Muscovite, Spodumene, Lepidolite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hydrokenomicrolite form in?+

Where it forms: An accessory mineral in the heavy mineral concentrate from a zoned granitic pegmatite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is hydrokenomicrolite used for?+

Hydrokenomicrolite is used in collector.

Find hydrokenomicrolite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.