Carpholite is a distinct sorosilicate typically found as delicate, straw-like radiating fibers or sheaves in metamorphic environments. It is highly valued by collectors for its aesthetic radiating habits and vibrant straw-yellow color. It is most frequently encountered in low-grade regional metamorphic belts.

Hardness

5.5-6

Mohs

Luster

Silky, glistening

Streak

White

Transparency

Semitransparent

mineraluncommon

Carpholite

Hardness: 5.5-6
Luster: Silky, glistening
Streak: White
Transparency: Semitransparent

Is this carpholite?

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 carpholite with a known reference. Carpholite sits at Mohs 5.5-6, 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: silky, glistening.
4
Match the color range
Compare against the expected color range: straw yellow, greenish gray, yellowish brown.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: fibrous, massive, radial.

Often confused with

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

How to tell apart: Luster reads silky, glistening on Carpholite and vitreous on Tremolite.

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Often found alongside carpholite

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

All properties

Chemical formula: MnAl₂Si₂O₆(OH)₄
Mohs hardness: 5.5-6
Density: 2.935-3.031 g/cm³
Colors: Straw yellow Greenish gray Yellowish brown
Streak: White
Luster: Silky, glistening
Transparency: Semitransparent
Crystal system: Orthorhombic
Crystal habit: Fibrous, massive, radial
Cleavage: Perfect on {010}
Rarity: Uncommon
Uses: Collector
Host rock: In low-grade metamorphosed shales

Where rockhounds find carpholite

Classic worldwide localities

Meuville, Ardennes Mountains, Belgium
Wippra, Harz Mountains, Germany
Carrock mine, Caldbeck Fells, Cumbria, England
Kit Hill Consols, Stokeclimsland, in the Hingston Down Consols mine, near Calstock, and in the Stenna Gwynn mine, St. Stephen-in-Brannel, Cornwall, England
Fukuzumi mine, Kyoto Prefecture, Japan

Field-hunting tip

Where it forms: In low-grade metamorphosed shales. If you start seeing sudoite, manganoan garnet, chlorotoid in float, you are in the right ground. Typical habit: fibrous, massive, radial. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify carpholite?+

Mohs hardness is 5.5-6. Luster: silky, glistening. The streak is white. Common colors include straw yellow, greenish gray, yellowish brown.

Where is carpholite found?+

Notable localities include Meuville, Ardennes Mountains, Belgium; Wippra, Harz Mountains, Germany; Carrock mine, Caldbeck Fells, Cumbria, England; Kit Hill Consols, Stokeclimsland, in the Hingston Down Consols mine, near Calstock, and in the Stenna Gwynn mine, St. Stephen-in-Brannel, Cornwall, England; Fukuzumi mine, Kyoto Prefecture, Japan.

What rocks look like carpholite?+

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

What minerals are found with carpholite?+

Carpholite commonly co-occurs with Sudoite, Manganoan garnet, Chlorotoid, Fluorite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does carpholite form in?+

Where it forms: In low-grade metamorphosed shales. Working float back to the host body is the standard way to chase a fresh occurrence.

What is carpholite used for?+

Carpholite is used in collector.

Find carpholite on the map

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