Vuonnemite is a rare niobium-bearing silicate mineral found in agpaitic alkaline igneous rocks. It typically occurs as flattened, tabular crystals or as lamellar aggregates within pegmatitic dikes, showing a distinct pearly luster on cleavage faces.

Hardness

2-3

Mohs

Luster

Vitreous to greasy

Streak

White

Transparency

Transparent to translucent

mineralrareLomonosovite Group family

Vuonnemite

Hardness: 2-3
Luster: Vitreous to greasy
Streak: White
Transparency: Transparent to translucent

Is this vuonnemite?

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 vuonnemite with a known reference. Vuonnemite sits at Mohs 2-3, 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: vitreous to greasy.
4
Match the color range
Compare against the expected color range: light yellow, lemon yellow, greenish yellow.
5
Look at form & habit
Crystal system: triclinic. Typical habit: bladed, platy.

Often confused with

Vuonnemite vs. its common look-alikes, and how to tell them apart in the field.

mineral

Lomonosovite

Mohs 3-4

How to tell apart: Streak differs, so Vuonnemite leaves white, Lomonosovite leaves light rose-cinnamon.

Often found alongside vuonnemite

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

All properties

Chemical formula: Na₆Na₂Nb₂Na₃Ti(Si₂O₇)₂(PO₄)₂O₂(OF)
Mohs hardness: 2-3
Density: 3.13-3.15 g/cm³
Colors: Light yellow Lemon yellow Greenish yellow
Streak: White
Luster: Vitreous to greasy
Transparency: Transparent to translucent
Crystal system: Triclinic
Crystal habit: Bladed, platy
Cleavage: Perfect on {001}, and two others
Fluorescence: Greenish yellow under SW UV; pale greenish yellow under LW UV
Rarity: Rare
Uses: Collector, Scientific research
Host rock: Albitized alkalic rocks

Where rockhounds find vuonnemite

Classic worldwide localities

Gunnison, Gunnison Co., Colorado, USA
Mt. Eveslogchorr, Khibiny massif, and the Jubilee pegmatite, on Mt. Karnasurt, Lovozero massif, Kola Peninsula, Russia
Mont Saint-Hilaire and near Saint-Amable, Quebec, Canada

Field-hunting tip

Where it forms: Albitized alkalic rocks. If you start seeing nepheline, microcline, aegirine in float, you are in the right ground. Typical habit: bladed, platy. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify vuonnemite?+

Mohs hardness is 2-3. Luster: vitreous to greasy. The streak is white. Common colors include light yellow, lemon yellow, greenish yellow.

Where is vuonnemite found?+

Notable localities include Gunnison, Gunnison Co., Colorado, USA; Mt. Eveslogchorr, Khibiny massif, and the Jubilee pegmatite, on Mt. Karnasurt, Lovozero massif, Kola Peninsula, Russia; Mont Saint-Hilaire and near Saint-Amable, Quebec, Canada.

What rocks look like vuonnemite?+

Vuonnemite is most often confused with Lomonosovite, Murmanite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with vuonnemite?+

Vuonnemite commonly co-occurs with Nepheline, Microcline, Aegirine, Eudialyte, Arfvedsonite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does vuonnemite form in?+

Where it forms: Albitized alkalic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is vuonnemite used for?+

Vuonnemite is used in collector, scientific research.

Find vuonnemite on the map

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