chalcedony

American  

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

noun

• chalcedonies
  plural

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

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chalcedony British  

/ kælˈsɛdənɪ, ˌkælsɪˈdɒnɪk /

noun

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

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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 .

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Other Word Forms

Derived Forms

• chalcedonic
  adjective
• chalcedonous
  adjective

Inflected Forms

Nouns

• chalcedonies
  plural

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

See Examples For:

chalcedony chalcedonies

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

The outfit was by 4SDesigns, but that the accompanying chain around his neck was an 18-karat white gold, platinum, chalcedony, turquoise and diamond necklace by Cartier somewhat complicated the point.

From New York Times ● May 3, 2022

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 box was carved wood, its mother-of-pearl lid inlaid with jasper and chalcedony.

From "A Clash of Kings" by George R.R. Martin

But flint is the staple of the broad Culm Valley, under good, well-pastured loam; and here are chalcedonies and agate stones.

From Crocker's Hole From "Slain By The Doones" By R. D. Blackmore by Blackmore, R. D. (Richard Doddridge)

There were rich red garnets, variegated jaspers, chalcedonies and agates of many hues mingled with rock-crystals.

From Wealth of the World's Waste Places and Oceania by Gilson, Jewett Castello

Many coloured and variegated chalcedonies are cut and polished as ornamental stones, and are described under special headings.

From Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 7 "Cerargyrite" to "Charing Cross" by Various

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 Hughes, J. Cecil

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

From Salammbo by Flaubert, Gustave