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Any of a group of chemically and physically related aluminum silicate minerals, common in igneous and metamorphic rocks, characteristically splitting into flexible sheets used in insulation and electrical equipment.

[Latin mīca, grain (perhaps influenced by micāre, to flash).]

mi·ca′ceous (-kā′shəs) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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Adj.1.micaceous - hydrous silicates of or relating to or resembling mica
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References in classic literature ?
The rock, also, being micaceous slate, there was no beach, but the steep sides dipped directly beneath the water.
Soils containing little or no micaceous mineral have less preferential bonding and selectivity for K, releasing a higher percentage of the exchangeable [K.sup.+].
The allophanic Egmont soil is dominated by variable charge clay components, such as allophane and kaolinite, and the Manawatu soil is dominated by permanent charge clay minerals, such as micaceous minerals.
It is dull black and unattractive but very rare in good "books" of micaceous crystals such as have recently been dug by Glenn Laidlaw, of Riverton, Wyoming, from the dumps of the now inactive Atlantic City iron mine, South Pass, Fremont County, Wyoming.
Effect of boiling nitric acid and sodium tetra phenyl boron on structural changes of micaceous clay minerals.
The crystals are typically white and micaceous in luster on the large c faces, but show an inner zone (sandwiched between the two main c faces) which is a deep, gemmy green.
The only problem is that at least some damage is almost always present, and is poignantly conspicuous: tiny bruises, especially on the wedge-tips of sheaves, stand out because of their lighter color and micaceous scaliness.
Some were cleaved off near the tip (so common with kammererite) or disfigured by tiny white micaceous bruises.
The mineral was found on a museum specimen, previously labeled as dixenite, from L[dot{a}]ngban, V[ddot{a}]rmland, Sweden, and occurs on one surface as red-brown to orange-brown aggregates of micaceous plates.
Psoriasis lesions may be annular, are more common on extensor surfaces, and usually have more prominent overlying pinkish, silvery white, or micaceous scale.