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 — that is 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.