I used to collect mica
obsessively from the fields in
Ontario where we
vacationed. Some was
milky, some was clear and
golden. There was
black mica and mica that reminded me of old
photos. I would dig it out of the ground or the road with my
grubby little fingers or a handy stick.
When we hiked in the woods, we would fairly commonly come across holes in the ground, pretty deep, pretty steep, fairly full of leaves and greens. These were mica mines. Apparently, because it's (at least somewhat) fireproof, it used to be used for the windows on ovens and in (fighter?) airplane windshields. These mines were often located near old foundations or abandoned houses, which i loved. I love the unclear and evocative, the abandoned and underground.
To test the fireproof theorem, i would sometimes throw some of my coveted finds into the campfire. I never found it later, in the pile of ashes, but that doesn't mean it was gone. Also, i would peel it, and thus make two of one. Four of two. But then again, the thinner pieces would crumble, and i would be left with fewer or out.
The shiny flecks in granite and gneiss are mica. Sometimes you even find chunks large enough to peel.