Chlorite is a common group of phyllosilicate minerals typically found in metamorphic environments or as an alteration product of other minerals. It is easily identified by its characteristic soft, green, platy, and micaceous nature, which feels slightly greasy to the touch. Collectors often seek out specimens where chlorite serves as a matrix for other minerals, such as quartz or adularia.
Is this chlorite?
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 chlorite with a known reference. Chlorite sits at Mohs 2-2.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Chlorite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Chlorite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: green, dark green, blackish green, yellowish green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, micaceous aggregates, massive, foliated.
Often confused with
Chlorite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside chlorite
Minerals reported to co-occur with chlorite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Mg,Fe)₃(Si,Al)₄O₁₀(OH)₂·(Mg,Fe)₃(OH)₆
- Mohs hardness
- 2-2.5
- Density
- 2.6-3.3 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy Crystals, Micaceous Aggregates, Massive, Foliated
- Cleavage
- Perfect Basal
- Rarity
- Common
- Uses
- Collector, Geological Indicator
- Host rock
- Metamorphic Rocks Like Schist and Phyllite, Or Hydrothermal Alteration Zones
- Typical price
- $5-30 thumbnail, $50-150 cabinet specimen
Where rockhounds find chlorite
29 mapped spotsClassic worldwide localities
- Austria
- Switzerland
- USA (Vermont, Pennsylvania)
- Norway
- Russia (Ural Mountains)
U.S. states with chlorite
Each link opens a state-specific list of mapped rockhounding spots that produce chlorite.
Field-hunting tip
Look in metamorphic rocks like schist and phyllite, or hydrothermal alteration zones country — that is the host setting where chlorite typically forms. If you start seeing quartz, albite, adularia in float, you are in the right ground. Field specimens usually show a platy crystals, micaceous aggregates, massive, foliated habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah, Pennsylvania, Wisconsin — start trip planning there.
Common questions
How do you identify chlorite?+
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Can I find chlorite in the United States?+
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Find chlorite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
