Mica is a general term for a group of phyllosilicate minerals that form thin, flexible, elastic sheets that can be easily peeled apart. It is a common constituent of igneous and metamorphic rocks, often found in granitic pegmatites as large books. Collectors prize specimens that show clear, well-defined books or larger sheets that demonstrate its perfect cleavage.
Is this mica?
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 mica with a known reference. Mica sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Mica leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Mica typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: black, brown, silver, white, green, yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, micaceous sheets, scaly aggregates.
Often confused with
Mica vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside mica
Minerals reported to co-occur with mica. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KAl₂(AlSi₃O₁₀)(OH)₂
- Mohs hardness
- 2-3
- Density
- 2.7-3.3 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Micaceous Sheets, Scaly Aggregates
- Cleavage
- Perfect Basal Cleavage
- Rarity
- Common
- Uses
- Industrial, Insulation, Collector
- Host rock
- Igneous, Metamorphic, And Pegmatites
- Typical price
- $5-30 for typical specimens
Where rockhounds find mica
35 mapped spotsClassic worldwide localities
- India
- Brazil
- Madagascar
- Canada
- Russia
U.S. states with mica
Each link opens a state-specific list of mapped rockhounding spots that produce mica.
Field-hunting tip
Look in igneous, metamorphic, and pegmatites country — that is the host setting where mica typically forms. If you start seeing quartz, feldspar, tourmaline in float, you are in the right ground. Field specimens usually show a tabular crystals, micaceous sheets, scaly aggregates habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in North Carolina, Georgia, Maine — start trip planning there.
Common questions
How do you identify mica?+
Where is mica found?+
Can I find mica in the United States?+
How much is mica worth?+
What rocks look like mica?+
What minerals are found with mica?+
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Find mica on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
