Celadonite is a soft, micaceous mineral typically found filling cavities in volcanic rocks like basalt. It is most famous for its historical use as a natural pigment known as 'terre verte' or green earth, prized by painters for its subtle, earth-toned hues.
Is this celadonite?
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 celadonite with a known reference. Celadonite sits at Mohs ~2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: greenish white.
- 3Read the lusterHold the specimen under a strong light. Luster: dull.
- 4Match the color rangeCompare against the expected color range: gray green, bluish green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: aggregates, earthy, encrustations.
Often confused with
Celadonite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Celadonite leaves greenish white, Glauconite leaves light green.
How to tell apart: Streak differs, so Celadonite leaves greenish white, Chlorite leaves white; luster reads dull on Celadonite and pearly on Chlorite.
Often found alongside celadonite
Minerals reported to co-occur with celadonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KMgFeSi₄O₁₀(OH)₂
- Mohs hardness
- ~2
- Density
- 2.95-3.05 g/cm³
- Colors
- Streak
- Greenish white
- Luster
- Dull
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Aggregates, earthy, encrustations
- Cleavage
- {001}, perfect
- Rarity
- Common
- Uses
- Collector, Pigment
- Host rock
- Replaces primary ferromagnesian silicate minerals in altered intermediate to mafic volcanic rocks, developed under low-grade zeolite facies metamorphism; as amygdule fillings in basalts or andesites
Where rockhounds find celadonite
1 mapped spotsClassic worldwide localities
- John Day Formation, Grant Co., Oregon, USA
- Mt. Rainier National Park, Pierce Co., Washington, USA
- Red Rock Canyon, Kern Co., California, USA
- Mt. Baldo, near Verona, Vicenza, and at Val di Fassa, Trentino-Alto Adige, Italy
- Zillertal, Tirol, Austria
- Scuir Mohr, Scotland
Field-hunting tip
Where it forms: Replaces primary ferromagnesian silicate minerals in altered intermediate to mafic volcanic rocks, developed under low-grade zeolite facies metamorphism; as amygdule fillings in basalts or andesites. If you start seeing montmorillonite, clinoptilolite, heulandite in float, you are in the right ground. Typical habit: aggregates, earthy, encrustations. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in New Jersey. Start trip planning there.
Common questions
How do you identify celadonite?+
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What rocks look like celadonite?+
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Find celadonite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
