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chalcedony

American  
[kal-sed-uhn-ee, kal-suh-doh-nee] / kælˈsɛd ən i, ˈkæl səˌdoʊ ni /

noun

  • chalcedonies
    plural
  1. a microcrystalline, translucent variety of quartz, often milky or grayish.


chalcedony British  
/ kælˈsɛdənɪ /

noun

  1. a microcrystalline often greyish form of quartz with crystals arranged in parallel fibres: a gemstone. Formula: SiO 2

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

chalcedony Scientific  
/ kăl-sĕd′n-ē /
  1. A type of quartz that has a waxy luster and varies from transparent to translucent. It is usually white, pale-blue, gray, brown, or black and is often found as a lining in cavities. Agate, flint, and onyx are forms of chalcedony. Chemical formula: SiO 2 .


Other Word Forms

Derived Forms

Inflected Forms

Nouns

Etymology

Origin of chalcedony

First recorded in 1275–1325; Middle English calcedonie, from Late Latin chalcēdōnius (Vulgate, Revelation 21:19), equivalent to chalcēdōn- (from Greek chalkēdṓn “chalcedony,” identified by Saint Jerome with Chalcedon, the city) + -ius adjective suffix; see -ious

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Encased in blue chalcedony, set with diamonds and hung from a black silk ribbon, the piece is a contemporary interpretation of Baillères’ Mexican heritage.

From Los Angeles Times ● Apr. 9, 2026

Watts gleamed in jewels, pairing her pavé diamond rings with a dazzler of a sapphire, diamond and chalcedony necklace.

From Los Angeles Times ● Feb. 19, 2015

The subtle color mixes included lilac diamonds with lavender chalcedony, purple sapphires and pink spinels.

From New York Times ● Jul. 4, 2011

The National Museum of the American Indian displays about 100 Pepper artifacts near the fourth-floor elevator entrance, mostly jasper and chalcedony blades that date back as far as 10,000 B.C.

From New York Times ● Jul. 22, 2010

He’s also brought down a few pieces of furniture I recognize from the palace—a silk-embroidered divan, satin cushions, a shimmering spider-silk throw, and a chalcedony set of tea things.

From "The Cruel Prince" by Holly Black

The diamonds of this district are noted for their purity and lustre, and are generally associated with other crystals—garnets, agates, quartz and chalcedonies.

From Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 3 "Banks" to "Bassoon" by Various

Ceraunia, engendered by the thunder, sparkled by the side of chalcedonies, which are a cure for poison.

From Salammbo by Gustave Flaubert

She had filled her pockets with specimens of obsidian, jaspers, and chalcedonies, of colors most beautiful, with a deep-dyed opaqueness, a shell-fracture, and a satiny polish like jade.

From A Touch of Sun and Other Stories by Mary Hallock Foote

Even precious stones are not wanting; garnets, topazes, tourmalines, amethysts, beryls, jaspers, and chalcedonies having been found.

From A Tramp's Wallet stored by an English goldsmith during his wanderings in Germany and France by William Duthie

The flints in Sandown Bay have in the main travelled round from here; and towards the Culvers small handy specimens of agates and chalcedonies rounded by the waves may be collected.

From The Geological Story of the Isle of Wight by J. Cecil Hughes

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