Pyrophyllite is a phyllosilicate mineral characterized by its greasy feel and soft, pearly appearance, often resembling talc. It typically forms in foliated or massive aggregates within metamorphic environments and is highly valued for its heat-resistant properties in industrial applications.

Hardness

1-2

Mohs

Luster

Pearly to dull

Streak

White

Transparency

Translucent to opaque

mineralcommon

Pyrophyllite

Also: agalmatolite

Hardness: 1-2
Luster: Pearly to dull
Streak: White
Transparency: Translucent to opaque

Is this pyrophyllite?

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 pyrophyllite with a known reference. Pyrophyllite sits at Mohs 1-2, 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: pearly to dull.
4
Match the color range
Compare against the expected color range: white, gray, pale green, yellow, brown, brown green, brownish yellow, greenish, gray green, gray white.
5
Look at form & habit
Crystal system: triclinic. Typical habit: earthy.

Often confused with

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

How to tell apart: Luster reads pearly to dull on Pyrophyllite and vitreous to pearly or silky on Muscovite.

Often found alongside pyrophyllite

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

All properties

Chemical formula: Al₂Si₄O₁₀(OH)₂
Mohs hardness: 1-2
Density: 2.65-2.90 g/cm³
Colors: White Gray Pale green Yellow Brown Brown green Brownish yellow Greenish Gray green Gray white
Streak: White
Luster: Pearly to dull
Transparency: Translucent to opaque
Crystal system: Triclinic
Crystal habit: Earthy
Cleavage: Perfect on {001}
Fluorescence: Butter yellow under LW UV
Rarity: Common
Uses: Industrial, Collector, Decorative, Refractory material
Host rock: Somewhat uncommon, found both in hydrothermal veins and in bedded deposits in schistose metamorphic rocks

Where rockhounds find pyrophyllite

3 mapped spots

Classic worldwide localities

Found near Ogilby, Imperial Co., at Tres Cerritos, Mariposa Co., and the Champion mine, White Mountains, Mono Co., California, USA
Quartzsite, La Paz Co., Arizona, USA
Staley, Randolph Co., Glendon and Robbins, Moore Co., and Hillsborough, Orange Co., North Carolina, USA
Brewer mine, Chesterfield Co., South Carolina, USA
Krassik, between Pyschminsk and Beresov, Ural Mountains, Russia
St. Niklas, Zermatt, Valais, Switzerland

Field-hunting tip

Where it forms: Somewhat uncommon, found both in hydrothermal veins and in bedded deposits in schistose metamorphic rocks. If you start seeing kyanite, andalusite, topaz in float, you are in the right ground. Typical habit: earthy. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in North Carolina, Georgia. Start trip planning there.

Browse 3 U.S. spots for pyrophyllite →

Common questions

How do you identify pyrophyllite?+

Mohs hardness is 1-2. Luster: pearly to dull. The streak is white. Common colors include white, gray, pale green, yellow.

Where is pyrophyllite found?+

Notable localities include Found near Ogilby, Imperial Co., at Tres Cerritos, Mariposa Co., and the Champion mine, White Mountains, Mono Co., California, USA; Quartzsite, La Paz Co., Arizona, USA; Staley, Randolph Co., Glendon and Robbins, Moore Co., and Hillsborough, Orange Co., North Carolina, USA; Brewer mine, Chesterfield Co., South Carolina, USA; Krassik, between Pyschminsk and Beresov, Ural Mountains, Russia.

Can I find pyrophyllite in the United States?+

RockHoundR maps 3 pyrophyllite rockhounding spots across 2 U.S. states. The top states are North Carolina, Georgia.

What rocks look like pyrophyllite?+

Pyrophyllite is most often confused with Talc, Muscovite, Kaolinite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with pyrophyllite?+

Pyrophyllite commonly co-occurs with Kyanite, Andalusite, Topaz, Mica, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does pyrophyllite form in?+

Where it forms: Somewhat uncommon, found both in hydrothermal veins and in bedded deposits in schistose metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is pyrophyllite used for?+

Pyrophyllite is used in industrial, collector, decorative, refractory material.

Find pyrophyllite on the map

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