Caryopilite is a rare manganese-rich phyllosilicate that typically occurs in metamorphosed sedimentary manganese deposits. It is most often found as massive or fibrous aggregates with a distinct pearly luster and a characteristic brownish color, and is prized by mineral collectors specializing in manganese species.
Is this caryopilite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch caryopilite with a known reference. Caryopilite sits at Mohs 3-3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: light brown.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: reddish brown, yellow, greenish brown, orange brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: massive, platy, pseudo hexagonal.
Often confused with
Caryopilite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Caryopilite leaves light brown, Serpentine leaves white; luster reads vitreous on Caryopilite and greasy on Serpentine.
How to tell apart: Streak differs, so Caryopilite leaves light brown, Friedelite leaves pale rose.
Often found alongside caryopilite
Minerals reported to co-occur with caryopilite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mn₃Si₂O₅(OH)₄
- Mohs hardness
- 3-3.5
- Density
- 2.83-2.94 g/cm³
- Streak
- Light brown
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Massive, platy, pseudo hexagonal
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A product of the metamorphism of manganese-bearing minerals
Where rockhounds find caryopilite
Classic worldwide localities
- Franklin and Sterling Hill, Ogdensburg, Sussex Co., New Jersey, USA
- Bald Knob, near Sparta, Alleghany Co., North Carolina, USA
- Hurricane mine, on the Olympic Penninsula, Washington, USA
- Harstigen mine, near Persberg, and at Långban, Värmland, Sweden
- Molinello and Gambatesa manganese mines, near Chiavari, Val Graveglia, Liguria, Italy
- Falotta mine, Oberhalbstein, Graubünden, Switzerland
Field-hunting tip
Where it forms: A product of the metamorphism of manganese-bearing minerals. If you start seeing gonyerite, calcite, rhodonite in float, you are in the right ground. Typical habit: massive, platy, pseudo hexagonal. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify caryopilite?+
Where is caryopilite found?+
What rocks look like caryopilite?+
What minerals are found with caryopilite?+
What kind of rock does caryopilite form in?+
What is caryopilite used for?+
Find caryopilite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
