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

Lamp-maker Sue Johnson says her small California business has been hit hard by tariffs, which prompted her supplier to roughly double the price of mica, a material she uses in her Art Deco-inspired designs.

From BBC ● Apr. 10, 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

The presence of materials such as obsidian, mica, seashells and shark teeth made clear to archaeologists that ceremonies held at the sites some 2,000 to 1,600 years ago attracted Indigenous peoples from across the continent.

From Seattle Times ● Oct. 14, 2023

As he knew, these were deflected somewhat by magnetic fields but, curiously, even more on their passage through solid matter—even through a thin film such as mica.

From "Big Science" by Michael Hiltzik

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

Most gneiss has little or no mica because it forms at temperatures higher than those under which micas are stable.

From Textbooks ● Jan. 1, 2015

The quartz crystals show no alignment, but the micas are all aligned, indicating that there was directional pressure during regional metamorphism of this rock.

From Textbooks ● Jan. 1, 2015

At 15 km to 20 km, larger micas form to produce schist, and at 20 km to 25 km amphibole, feldspar, and quartz form to produce gneiss.

From Textbooks ● Jan. 1, 2015

The felspar is pearly, white or pink, with smooth cleaved surfaces; the quartz is usually transparent, glassy with rough irregular fractures; the micas appear as shining black or white flakes.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 3 "Gordon, Lord George" to "Grasses" by Various