A mica book is a large, thick, layered crystal of a mica mineral such as muscovite or phlogopite, found within granitic pegmatite. It is valued for cleaving into thin, flexible, often transparent sheets that demonstrate its perfect basal cleavage.
Is this mica book?
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 book with a known reference. Mica Book sits at Mohs 2.5-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Mica Book leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Mica Book typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: black, brown, silver, clear, green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular, pseudohexagonal, platy crystals.
Often confused with
Mica Book vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside mica book
Minerals reported to co-occur with mica book. 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
- 2.5-4
- Density
- 2.7-3.3 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular, Pseudohexagonal, Platy Crystals
- Cleavage
- Perfect Basal
- Rarity
- Common
- Uses
- Industrial, Collector, Decorative
- Host rock
- Pegmatites
Where rockhounds find mica book
1 mapped spotsClassic worldwide localities
- India
- Brazil
- Madagascar
- Canada
- USA
Field-hunting tip
Look in pegmatites country, the host setting where mica book typically forms. If you start seeing quartz, feldspar, garnet in float, you are in the right ground. Field specimens usually show a tabular, pseudohexagonal, platy crystals habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Georgia. Start trip planning there.
More mica book photos
Common questions
How do you identify mica book?+
Where is mica book found?+
Can I find mica book in the United States?+
What rocks look like mica book?+
What minerals are found with mica book?+
What kind of rock does mica book form in?+
What is mica book used for?+
Find mica book on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
