chalcedony

American  

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

noun

plural

chalcedonies

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

• chalcedonic adjective
• chalcedonous adjective

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; -ious

Example Sentences

One supposed mammal tooth was actually a bit of the mineral chalcedony.

From New York Times • Feb. 21, 2023

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

Despite the pilferings of ancient vandals, countless beads of lapis lazuli, carnelian, crystal, shell, marble, chalcedony and gold still encircled the necks and hips of crumbling skeletons with tightly bent legs.

From Time Magazine Archive

With any luck, the territory would contain flint, jasper, or chalcedony, the raw material for spear points, meat scrapers, and other hunting tools.

From "1491" by Charles C. Mann