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.

Mi"ca (?), n. [L. mica crumb, grain, particle; cf. F. mica.] Min.

The name of a group of minerals characterized by highly perfect cleavage, so that they readily separate into very thin leaves, more or less elastic. They differ widely in composition, and vary in color from pale brown or yellow to green or black. The transparent forms are used in lanterns, the doors of stoves, etc., being popularly called isinglass. Formerly called also cat-silver, and glimmer.

The important species of the mica group are: muscovite, common or potash mica, pale brown or green, often silvery, including damourite (also called hydromica); biotite, iron-magnesia mica, dark brown, green, or black; lepidomelane, iron, mica, black; phlogopite, magnesia mica, colorless, yellow, brown; lepidolite, lithia mica, rose-red, lilac.

Mica (usually muscovite, also biotite) is an essential constituent of granite, gneiss, and mica slate; biotite is common in many eruptive rocks; phlogopite in crystalline limestone and serpentine.

Mica diorite Min., an eruptive rock allied to diorite but containing mica (biotite) instead of hornblende. -- Mica powder, a kind of dynamite containing fine scales of mica. -- Mica schist, Mica slate Geol., a schistose rock, consisting of mica and quartz with, usually, some feldspar.


© Webster 1913.

Log in or registerto write something here or to contact authors.