a mineral, an amorphous form of silica, SiO 2 with some water of hydration, found in many varieties and colors, including a form that is milky white.
an iridescent variety of this that is used as a gem.
a gem of this.
What does opal mean? An opal is a gemstone that’s best known for its iridescent, milky-white variety. Other varieties are black and gray, but it can be almost any color. As a mineral, opal is a form of silica. Unlike many of the other gemstones used in jewelry, opal is not crystalline, meaning it does not form in a crystal structure—it looks like a stone, as opposed to a faceted jewel like a diamond. Opal gemstones are classified as common or precious. Precious is a label given to certain gemstones that are high in value. Opals labeled precious are typically those that display a high level of iridescence. Opal is the traditional birthstone for the month of October. It is associated with the zodiac signs Libra and Scorpio. Example: The opal pendant had flecks of green, pink, and blue.
1350–1400; Middle English < Latin opalus < Greek opállios opal, gem; probably from a source akin to Sanskrit upala precious stone
An opal is a gem, a semi-precious stone that comes in many shimmery, partly translucent colors. If your birthday is in October, an opal is your birthstone. An opal is a mineral made of silica, and it's found within the cracks and notches of many different kinds of rock. Most of the world's supply of opals comes from Australia. A polished opal that's been set in a ring or necklace is usually several shades or colors — most often blues and greens — with sparkles or shimmers decorating the stone. The word opal comes from the Latin opalus, and its ultimate root is probably the Sanskrit upala, "precious stone."
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The broth is still at the center of all things La Mer: Past celebrations have involved “broth-tinis,” which are just cocktails made to resemble the opal liquid with its root beer smell.
From The Wall Street Journal ● Mar. 18, 2026
The array of fossils were found about 25 years ago by palaeontologist Elizabeth Smith and her daughter Clytie while they were going through the discards of an opal mine.
From BBC ● May 27, 2024
Found in the Lightning Ridge opal fields, NSW, the opalised jaws date back to the Cenomanian Age of the Cretaceous Period, between 102 million to 96.6 million years ago.
From Science Daily ● May 27, 2024
Melinda Maria’s 17- to 20-inch white opal necklace pairs nicely with shorter strands if your giftee loves to wear a layered stack.
From Los Angeles Times ● Nov. 1, 2023
Over the past weeks in Paris, in the hours between other tasks, he has narrowed a list of seven lapidaries to three, then to one: a half-Algerian named Dupont who came of age cutting opal.
From "All the Light We Cannot See" by Anthony Doerr
We heard from a mother, Opal Foster, whose 18-year-old son has Down syndrome and lives at home as he strives to become a chef.
From Salon ● Apr. 29, 2026
Donkeys, including a couple, Clyde and Opal, patrol the vineyards to fend off coyotes, while chickens and sheep rotate through the rows, and hawks and owls are nurtured to deter rodents.
From Los Angeles Times ● Oct. 29, 2025
Santos said a software issue affecting safety systems on board the BW Opal floating production storage and offloading unit had led to an unplanned shutdown of around two weeks last month.
From The Wall Street Journal ● Oct. 16, 2025
As a reviewer for Dazed pointed out, “using Opal just made me want to look at my phone even more.”
From Slate ● Sep. 5, 2025
I shouted to Opal, and sat down at the spinning wheel.
From "Rump: The (Fairly) True Story of Rumpelstilskin" by Liesl Shurtliff
At moments, as the rays of the setting sun flooded across the Potomac River, the upper branches of many trees seemed to glow as might a sea of opals and rubies.
From Washington Post ● Apr. 2, 2022
The opal, dubbed the “Americus Australis,” weighs more than 11,800 carats and is one of the largest gem-quality opals in existence, according to the auction house Alaska Premier Auctions & Appraisals.
From Seattle Times ● Feb. 20, 2022
Some of Ms. Harris’s designs come in solid gold and others in platinum; many are clustered with brilliant diamonds or opals.
From New York Times ● Jan. 27, 2022
From the window seat of a 737, they look like flickering blue opals embedded in a matrix of dusty greenery and concrete.
From Los Angeles Times ● Jul. 13, 2021
She was looking at herself in the mirror, remembering the pale blue silk dress with the pink flowers and the gold necklace with rubies and opals.
From "Ruby Holler" by Sharon Creech
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.
