Oxynatromicrolite is a rare member of the pyrochlore supergroup occurring primarily in tantalum-rich granitic pegmatites. It is typically found as small, octahedral crystals or massive grains and is highly sought after by collectors specializing in complex oxide species.

Hardness

5-5.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrarePyrochlore Supergroup family

Oxynatromicrolite

Hardness: 5-5.5
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this oxynatromicrolite?

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

Often found alongside oxynatromicrolite

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

All properties

Chemical formula: (Na,Ca,◻)₂(Ta,Nb)₂O₆(O,OH,F)
Mohs hardness: 5-5.5
Density: 5.5-6.5 g/cm³
Colors: Yellow Brown Colorless
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Octahedral Crystals, Massive
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find oxynatromicrolite

Classic worldwide localities

Sweden
Russia
Brazil
Canada

Field-hunting tip

Look in granite pegmatites country — that is the host setting where oxynatromicrolite typically forms. If you start seeing albite, quartz, microcline in float, you are in the right ground. Field specimens usually show a octahedral crystals, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify oxynatromicrolite?+

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

Where is oxynatromicrolite found?+

Notable localities include Sweden; Russia; Brazil; Canada.

How much is oxynatromicrolite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is oxynatromicrolite safe to handle?+

This mineral is radioactive. Contains minor amounts of radioactive elements like thorium and uranium; wash hands after handling and store away from prolonged contact. Handle with care, avoid grinding or breathing dust, and store separately.

What minerals are found with oxynatromicrolite?+

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

What kind of rock does oxynatromicrolite form in?+

Oxynatromicrolite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is oxynatromicrolite used for?+

Oxynatromicrolite is used in collector.

Find oxynatromicrolite on the map

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