mica

American  

[mahy-kuh] / ˈmaɪ kə /

noun

• micas
  plural

1. any member of a group of minerals, hydrous silicates of aluminum with other bases, chiefly potassium, magnesium, iron, and lithium, that separate readily into thin, tough, often transparent, and usually elastic laminae; isinglass.

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mica British  

/ maɪˈkeɪʃəs, ˈmaɪkə /

noun

1. any of a group of lustrous rock-forming minerals consisting of hydrous silicates of aluminium, potassium, etc, in monoclinic crystalline form, occurring in igneous and metamorphic rock. Because of their resistance to electricity and heat they are used as dielectrics, in heating elements, etc

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mica Scientific  

/ mī′kə /

1. Any of a group of hydrous aluminosilicate minerals with the general formula (K,Na,Ca)(Mg,Fe,Li,Al) _2–3 (Al,Si) ₄ O ₁₀ (OH,F) ₂ that can be split easily into thin, partly transparent sheets. Mica is common in igneous and metamorphic rocks and often occurs as flakes or sheets. It is highly resistant to heat and is used in electric fuses and other electrical equipment. Muscovite and biotite are types of mica

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Other Word Forms

Derived Forms

• micaceous
  adjective
• micalike
  adjective

Inflected Forms

Nouns

• micas
  plural

Etymology

Origin of mica

First recorded in 1700–10, mica is from the Latin word mīca crumb, morsel, grain

Example Sentences

See Examples For:

mica micas

On the east side, the dam was build atop an ancient landslide of mica schist, a type of rock vulnerable to fracturing that would allow moisture to seep inside.

From Los Angeles Times ● Aug. 6, 2026

A hard-edged 1928 coffee table may be made of oak, but it’s covered in shimmering mica.

From The Wall Street Journal ● Dec. 23, 2025

Black Barn Apiary’s Luxe Gold Honey is infused with edible gold mica and made on 20 acres of restored native prairie land in Wisconsin.

From Salon ● Apr. 18, 2025

In November 2021, the Irish government introduced what it said was a significant number of improvements to a previous scheme for mica homeowners.

From BBC ● Nov. 27, 2024

I climbed up, slipping and floundering, lost the echoed light and found it again, a good little new-split stone with a piece of mica in it—not a fortune but a good thing to have.

From "Travels with Charley in Search of America" by John Steinbeck

Two frequently found micas are dark-colored biotite, frequently found in granite, and light-colored muscovite, found in the metamorphic rock called schist.

From Textbooks ● Jan. 1, 2017

Muscovite micas belong to the felsic silicate minerals.

From Textbooks ● Jan. 1, 2017

On the other hand, most clay minerals are only stable up to about 150° or 200°C; above that, they transform into micas.

From Textbooks ● Jan. 1, 2015

Phyllite is similar to slate, but has typically been heated to a higher temperature; the micas have grown larger and are visible as a sheen on the surface.

From Textbooks ● Jan. 1, 2015

They hung from branches of almandine and ouwarovite of a violet red, darting spangles of a hard brilliance like tartar micas gleaming through forest depths.

From Against the Grain by J.-K. (Joris-Karl) Huysmans