a variegated chalcedony showing curved, colored bands or other markings.
a playing marble made of this substance, or of glass in imitation of it.
Printing. a 5½-point type of a size between pearl and nonpareil.
an impure microcrystalline form of quartz consisting of a variegated, usually banded chalcedony, used as a gemstone and in making pestles and mortars, burnishers, and polishers. Formula: SiO 2
a playing marble of this quartz or resembling it
Also called: ruby. printing (formerly) a size of printer's type approximately equal to 5 1/ 2 point
What is agate? Agate is a variety of the mineral chalcedony (a type of quartz), specifically one with bands or stripes or other markings. It is often considered a gemstone. It can occur in a wide variety of colors, including white, yellow, red, and black. The key quality of agate is its banding, which is crystal that has formed in the rock. Agate is considered a semiprecious stone, which is a label assigned to some stones that have a lesser value than those considered precious. When used in jewelry, agate is often cut into a shape called a cabochon, which is polished but not cut into facets. When loose (not set in jewelry), they are often sold in the form of a geode or slab. Several forms of chalcedony are considered agates if they contain banding, including the gemstones onyx and sardonyx. Specific kinds of agate are named for their colors and patterns. For example, moss agate features a green pattern that resembles moss. Agate is one of the traditional birthstones for the months of May and June. It is associated with the zodiac sign Gemini. Example: I bought a beautiful yellow agate geode at the rock and crystal shop.
1150–1200; Middle English ac ( c ) ate, achate, agaten (compare Dutch agaat, Old Saxon agāt, Old High German agat ), apparently < Old French agathe or Italian agata (initial stress) ≪ Medieval Latin achātēs < Greek achā́tēs
Agate is a gemstone that's similar to quartz. Jewelry, including pins and earrings, is sometimes made from agate. Agate is mainly found in volcanic rock, and it's often distinguished by its lines or bands, a result of silicate material layering as it filled in cracks in these ancient rocks. Agate has long been used for carving ornaments and vessels, including beads, marbles, jewelry, mortars, and pestles. The name agate comes from the Greek akhates, the name of a river in Sicily where the stone was commonly found about 3,000 years ago.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
A tireless researcher, Bauer tries to keep a record of her purchases, from the colorful vintage Bauer pottery ringware in her kitchen to the Akro Agate glassware in her guest room.
From Los Angeles Times • Oct. 20, 2025
Latvian teenager Agate Caune used a bold strategy in heat one of the 5,000.
From Washington Times • Aug. 23, 2023
Joe Agate, 27, from Chorley in Lancashire, was proudly wearing an England top around the Souk on Wednesday, but at the game he was "in disguise in The Red Wall".
From BBC • Nov. 30, 2022
Back in Winslow, before boarding the ferry, I stopped for lunch at Agate, a farm-to-table eatery with a muted glamour that feels inspired by Venice Beach.
From Washington Post • Aug. 5, 2022
L. N. Channing of the Agate Point radio transmitter station, addressed the defense commission meeting.
From "Snow Falling on Cedars: A Novel" by David Guterson
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
