Sericite is a fine-grained, silky variety of muscovite that typically occurs as an alteration product in metamorphic rocks. It is easily identified by its characteristic pearly, greasy luster and its soft, scaly, or micaceous aggregate habit.
Is this sericite?
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 sericite with a known reference. Sericite 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. Sericite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Sericite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: white, silver, pale green, yellowish.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: fine-grained micaceous aggregates.
Often confused with
Sericite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside sericite
Minerals reported to co-occur with sericite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KAl₂Si₃AlO₁₀(OH)₂
- Mohs hardness
- 2-2.5
- Density
- 2.7-3.0 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Fine-grained Micaceous Aggregates
- Cleavage
- Perfect Basal
- Rarity
- Common
- Uses
- Industrial, Collector
- Host rock
- Hydrothermally Altered Metamorphic Rocks
- Typical price
- $5-20 for bulk samples
Where rockhounds find sericite
6 mapped spotsClassic worldwide localities
- Germany
- USA
- Japan
- United Kingdom
Field-hunting tip
Look in hydrothermally altered metamorphic rocks country — that is the host setting where sericite typically forms. If you start seeing quartz, pyrite, chlorite in float, you are in the right ground. Field specimens usually show a fine-grained micaceous aggregates habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Maine, Michigan, New Hampshire — start trip planning there.
Common questions
How do you identify sericite?+
Where is sericite found?+
Can I find sericite in the United States?+
How much is sericite worth?+
What rocks look like sericite?+
What minerals are found with sericite?+
What kind of rock does sericite form in?+
What is sericite used for?+
Find sericite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
