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Mica ("MIKE-uh") from Pegmatite

		Mica is an amazing mineral! It bends, and it peels into thinner and thinner pieces -- so thin that you can see through it. Although mica looks like glass, it won't cut you. The mica on the left formed as melted rock cooled slowly, far below the surface of the earth. To learn more about mica, scroll farther down this page.
Mica as loose flakes and in chunks of pegamatite.

	How to recognize mica
	Other rocks that look like mica
	Special things to do with mica
	Where mica came from
	How mica formed
	Other names for mica
	Links to Websites about mica

How to recognize mica

	Thick pieces look silvery.
	Mica breaks into thin, flat, flexible flakes -- you can see light through them!
	Mica is often stuck on or mixed with larger pink, white, and gray crystals.

Other minerals that look like mica

In our neighborhood, the only things that you
might mistake for mica are pieces of clear
plastic and broken glass.

Special things to do with mica

Try to do these things with mica:

(Picture to come later)	Peel it!

(Picture to come later)	Bend it!

(Picture to come later)	Look through it!

Where mica came from

Most big pieces of mica come from a type
of rock called pegmatite. We think the
pegmatite that we buy in our area came
from the Rocky Mountains in Colorado.

Gray slate is made, in part, of tiny flakes of
mica. Mica gives slate a satiny look.

How mica formed

Mica formed as melted rock cooled slowly,
far below the surface of the earth. Other
crystals also formed, like quartz and feldspar.
The growing crystals interlocked to make a
rock called pegmatite.

Other names for mica

We use the name "mica" for this mineral,
but it is also known by other names:

	The type of mica that we found is known as "white mica" or "muscovite."
	People used big sheets of mica to make windows for furnaces and other really hot places. When mica is used in this way, it's sometimes called "isinglass."
	The mica we've found in our area comes in 50-pound bags of pegmatite gravel labeled "Royal Gorge."

Here are some ways to classify mica (by grouping it with similar types of rocks):

	Mica is a mineral -- one of the building blocks of rocks like granite and slate.
	The mica that we found was part of an igneous rock.

Links to Websites about mica

Encarta® Concise Encyclopedia article on mica:
< http://encarta.msn.com/index/conciseindex/29/02962000.htm?z=1&pg=2&br=1 >

Article on the mica group of minerals, with a link
to more information on muscovite:
< http://mineral.galleries.com/minerals/silicate/micas.htm >

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This page was created on May 6, 2001, and it was last updated on July 27, 2002.