mica

Definitions

  • WordNet 3.6
    • n mica any of various minerals consisting of hydrous silicates of aluminum or potassium etc. that crystallize in forms that allow perfect cleavage into very thin leaves; used as dielectrics because of their resistance to electricity
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Webster's Revised Unabridged Dictionary
    • n 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 damouritealso called hydromica and muscovy glass); 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.Micausually 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.
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Century Dictionary and Cyclopedia
    • n mica A crumb; a little bit.
    • n mica One of a group of minerals all of which are characterized by their very perfect bassal cleavage, in consequence of which they can be separated easily into extremely thin, tough, and usually elastic laminæ. They occur in crystals with a prismatic angle of 120, but more commonly in crystalline aggregates, often of large plates, but sometimes of minute scales, having a foliated structure, the folia being generally parallel, but also concentric, wavy, and interwoven, and also arranged in stellate or plumose and sometimes almost fibrous forms. In crystallization the micas belong to the monoclinic system, but they approximate very closely in form in part to the orthorhombic system (e. g., muscovite), in part to the rhombohedral system (e. g., biotite). The micas are silicates of aluminium with other bases, as iron, calcium, magnesium, potassium, sodium, lithium; in some kinds fiuorin is present in small amount. The prominent varieties are—muscovite or common potash mica, the light-colored mica of granite and similar rocks, and paragonite, which is an analogous soda species; biotite, or magnesia mica (including meroxene and anomite, distinguished according to the position of the optic axial plane), the black or dark-green mica of granite, hornblende rocks, etc.; phlogopite, the bronze-colored species common in crystalline limestone and serpentine rocks; lepidomelane, a black mica containing a large amount of iron; and lepidolite, the rose-red or lilac lithia mica occurring commonly in aggregates of scales. (See further under these names.) The micas enter into the composition of many rocks, including the crystalline rocks, both metamorphic and volcanic (as granite, gneiss, mica-schist, trachyte, diorite, etc.), and sedimentary rocks (as shales and sandstones), sometimes giving them a laminated structure. In the sedimentary rocks they are in most cases derived from the disintegration of older crystalline rocks. Mica (muscovite) is often used in thin transparent plates for spectacles to protect the eyes in various mechanical processes, in reflectors, instead of glass in places exposed to heat, as in head-lights and stove- and lantern-lights, and even for windows in Russia (hence called Muscovy glass). Ground to powder, it is combined with varnish to make a glittering coating for wall-papers, and is used also in preparing a covering for roofs, and as a packing and lubricator for machinery. It is often vulgarly called isinglass. The so called brittle micas include a number of species, as margarite, seybertite (clintonite), etc., which are related to the true micas, but are characterized by their brittle folia.
    • n mica In the preparation of kaolin for use in the manufacture of porcelain, one of the second set of channels through which a mixture of water and suspended clay washed out by the water from the broken clay-bearing rock is slowly passed to obtain the deposition of flakes of mica and other foreign substances, and thus to purify the clay, which is finally allowed to subside in a series of pits or tanks. Each of the first set of channels through which the mixture is passed for the settling of the coarser flakes of mica, etc., is called a drag. This set of channels is collectively called the drags, and the second set the micas. See porcelain and kaolin.
    • n mica A prefix frequently used in lithology when the rock in question contains more or less mica in addition to the other usual constituents. Thus, mica-syenite, a rock differing very little from ordinary syenite; mica-trap, nearly the same as minette, etc.
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Chambers's Twentieth Century Dictionary
    • n Mica mī′ka a group of rock-forming minerals, with perfect cleavage in one direction, the laminæ flexible and elastic, and generally transparent
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Etymology

Webster's Revised Unabridged Dictionary
L. mica, crumb, grain, particle; cf. F. mica,
Chambers's Twentieth Century Dictionary
L. mica, a crumb.

Usage

In literature:

The big stove with its dozens of mica eyes threw out comforting little rays of coziness, but the real me still shivered.
"Letters of a Dakota Divorcee" by Jane Burr
A pleasant-looking man came forward, and I asked him what mica was worth.
"The Jucklins" by Opie Read
Inferior stones are found imbedded in mica slate in Europe.
"Boy Scouts in the Canal Zone" by G. Harvey Ralphson
L. It is rust of iron, finely crystallised: from its resemblance to mica, it is often called micaceous iron.
"The Crown of Wild Olive" by John Ruskin
The rain streaked the mica lights in the side-curtains.
"Free Air" by Sinclair Lewis
Mica, in quartz sand, 58.
"Conservation Reader" by Harold W. Fairbanks
Mica, analysis of, 105; potash in, 214, 220.
"Manures and the principles of manuring" by Charles Morton Aikman
For ground mica, the domestic production exceeds in tonnage the total world production of sheet mica, and is adequate for all demands.
"The Economic Aspect of Geology" by C. K. Leith
The gleaming something which he held aloft was nothing but a bit of discolored mica that had reflected the faint light.
"The Black Buccaneer" by Stephen W. Meader
Two square sheets of green colored mica rolled out from the bundle.
"Ralph on the Overland Express" by Allen Chapman
These can be backed up with mica or celluloid.
"Boys' Book of Model Boats" by Raymond Francis Yates
Micaceous, covered with glistening scales, mica-like.
"The Mushroom, Edible and Otherwise" by M. E. Hard
It is thus, thought we, that our manufacturers of fancy wax deal by their mica.
"Leading Articles on Various Subjects" by Hugh Miller
Granite often contains large crystals of felspar or mica.
"Boy Scouts Handbook" by Boy Scouts of America
There is no mica in the paste.
"A Burial Cave in Baja California" by William C. Massey
The flaming tapers were reflected in places from many points of quartz, or mica.
"The Girls of Central High on Lake Luna" by Gertrude W. Morrison
Small pieces of mica can be glued over the windows instead of glass.
"What Shall We Do Now?: Five Hundred Games and Pastimes" by Dorothy Canfield Fisher
The room was bathed in the half-light that came from the four dull panes of mica in the front of the great stove.
"The Monster and Other Stories" by Stephen Crane
The card is a mica disk, either painted as in fig.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 7" by Various
A COLORLESS CEMENT FOR JOINING SHEETS OF MICA.
"Paper and Printing Recipes" by J. Sawtelle Ford
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In poetry:

No more waves of housecoats: questions,
Even footsteps disappear;
Glassy mica fills the latticed
Work-encompassed vault of air.
"Humble home. But rum, and charcoal..." by Boris Pasternak
Visiting the nun Rise-In-Air,
You must be near her place in those blue hills.
The river’s force helps pound the mica,
The wind washes rose bay tree flowers.
If you find you can’t leave that refuge,
Invite me there to see the sunset’s fire.
"To My Wife on Lu-shan Mountain" by Li Po

In news:

Jerry Gibson, from left, Ken Honecker, Larry Honig, Paul Mayer, Amadeo Petricca, Larry Sacher, Duane Thomas, and Wayne Waldack MICA 's City Council Candidate Forum was held Wednesday evening at Rose History Auditorium.
Related Stories for MICA 's Marco City Council Candidate Forum.
John Mica To Speak At NBAA 2012 Opening General Session.
Ten-term Congressman John Mica has defeated freshman US Rep Sandy Adams following a tough primary battle that pitted two Florida Republican incumbents against each other because of redistricting.
Mica calls for unified approach to fund next surface transportation authorization.
Mica in Chestnut Hill.
Mica serves as chairman of the House Transportation Committee.
The National Endowment for the Arts has announced that MICA will receive a $150,000 grant from its inaugural round of "Our Town" funding.
Mica 's Proposed Bill Would Kill Guaranteed Bike/Ped Funding.
Chairman Mica released an outline of his proposal without bill text details calling for a six-year bill funded at approximately $230 billion.
Building America's Future Issues Statement on Chairman Mica 's Proposed Surface Transportation Reauthorization Briefing.
Boxer, Mica Bills $20 Billion Apart in Yearly Roads Funding.
Representative John L Mica , Republican of Florida, is one of the nation's top critics of expanded federal funding for passenger rail service provided by Amtrak.
Baltimore Fashion Blooms at MICA .
MICA & Globe Do the Right Thing.
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In science:

Rivetti et al. have studied at length the binding of DNA to Mg2+ -modified mica surfaces .
Reply to ``Comment on `Insulating Behavior of $\lambda$-DNA on the Micron Scale' "
Astronomers Not Expert in Stellar Dynamics To assess AstroSim’s impact in the astronomy communit y in general, we organized a session w ith 10 astronomers from the Meta Inst itute for Computat ional Astrophysics (Mica; ht tp://mica-vw.org) who had no stellar-dynamics exper t ise.
AstroSim: Collaborative Visualization of an Astrophysics Simulation in Second Life
When (111) BaF2 or mica substrates are used, the EMD grids appear to be incomplete or do not appear whatsoever.
Interface superconductivity: History, development and prospects
Paradigma de sistema complejo y el peor comprendido de nuestros ´organos, el cerebro es, esencialmente, una inmensa red de c´elulas que se comunican entre s´ı mediante se˜nales electro-qu´ımicas.
Interplay between Network Topology and Dynamics in Neural Systems
Meeker (2003) discuss an ALT for a new mica-based insulation design for generator armature bars (GABs).
A Review of Accelerated Test Models
An active source of actinium was covered with a sheet of mica and placed in a chamber.
Discovery of the thallium, lead, bismuth, and polonium isotopes
Discuto algunos de los resultados presentados en este simposio sobre: nebulosas planetarias, regiones H ii, evoluci´on qu´ımica de galaxias y la determinaci´on de la abundancia primordial de helio.
Temperature Structure and Chemical Abundances in Gaseous Nebulae
Indirect GUT MM searches used ancient mica, which has a high threshold.
Magnetic Monopole Searches
It is assumed that a pole passing through the Earth captures an Al nucleus and drags it through subterranean mica causing a trail of lattice defects, which survive as long as the mica is not reheated.
Magnetic Monopole Searches
Indirect searches with old mica samples could yield the lowest limits, but they are affected by several uncertainties.
Magnetic Monopole Searches
Desde hace ya varias d´ecadas, los c´umulos abiertos han sido utilizados para estudiar la estructura y evoluci´on qu´ımica del disco de la Galaxia.
Analysis of the chemical evolution of the Galactic disk via dynamical simulations of the open cluster system
En el presente traba jo analizamos la historia de formaci´on estelar y la evoluci´on qu´ımica del disco de la Galaxia utilizando simulaciones num´ericas de la evoluci´on din´amica del sistema de c´umulos abiertos de la Galaxia.
Analysis of the chemical evolution of the Galactic disk via dynamical simulations of the open cluster system
La comparaci´on de dichos modelos con las observaciones nos permite examinar la validez de las hip´otesis asumidas y mejorar nuestro conocimiento acerca de las condiciones iniciales de la evoluci´on qu´ımica del disco gal´actico.
Analysis of the chemical evolution of the Galactic disk via dynamical simulations of the open cluster system
Typical representative Li of mineral origin is mica.
Fugacity of condensed media
Mica — is one of the most wide spread minerals of rocks.
Fugacity of condensed media
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