Yofortierite is a rare manganese-bearing silicate mineral belonging to the sepiolite group. It typically appears as fibrous or needle-like white to pink aggregates within cavities of nepheline syenite rocks.

Hardness

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineralrareSepiolite Group family

Yofortierite

Hardness: 2
Luster: Pearly
Streak: White
Transparency: Translucent

Is this yofortierite?

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 yofortierite with a known reference. Yofortierite sits at Mohs 2, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Yofortierite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Yofortierite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: white, pink, pale red.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: fibrous, acicular, asbestos-like.

Often confused with

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

mineral

Sepiolite

Mohs 2-2.5

How to tell apart: Luster reads pearly on Yofortierite and dull on Sepiolite.

How to tell apart: Luster reads pearly on Yofortierite and dull on Palygorskite.

Compare →

Often found alongside yofortierite

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

All properties

Chemical formula: Mn₅Si₈O₂₀(OH)₂·8-9H₂O
Mohs hardness: 2
Density: 2.16 g/cm³
Colors: White Pink Pale Red
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Fibrous, Acicular, Asbestos-like
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Nepheline Syenite Pegmatites
Typical price: $20-150 per specimen

Where rockhounds find yofortierite

Classic worldwide localities

Mont Saint-Hilaire, Quebec, Canada
Kola Peninsula, Russia

Field-hunting tip

Look in nepheline syenite pegmatites country, the host setting where yofortierite typically forms. If you start seeing quartz, albite, microcline in float, you are in the right ground. Field specimens usually show a fibrous, acicular, asbestos-like habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify yofortierite?+

Mohs hardness is 2. It typically shows a pearly luster. The streak is white. Common colors include white, pink, pale red.

Where is yofortierite found?+

Notable localities include Mont Saint-Hilaire, Quebec, Canada; Kola Peninsula, Russia.

How much is yofortierite worth?+

Typical asking prices fall in the range of $20-150 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like yofortierite?+

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

What minerals are found with yofortierite?+

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

What kind of rock does yofortierite form in?+

Yofortierite typically forms in nepheline syenite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is yofortierite used for?+

Yofortierite is used in collector.

Find yofortierite on the map

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