[ on-iks, oh-niks ]
/ ˈɒn ɪks, ˈoʊ nɪks /
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Mineralogy. a variety of chalcedony having straight parallel bands of alternating colors.Compare Mexican onyx.
(not used technically) an unbanded chalcedony dyed for ornamental purposes.
black, especially a pure or jet black.
Medicine/Medical. a nail of a finger or toe.
black, especially jet black.
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Origin of onyx

1250–1300; Middle English onix<Latin onyx<Greek ónyx nail, claw, veined gem
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


What does onyx mean?

Onyx is a gemstone that’s especially known for its opaque, all-black variety.

Other varieties are black with with different-colored layers, including white.

Onyx is commonly used in jewelry. Historically, onyx was popular as a material for cameos—engraved gems. Sometimes, it is dyed or artificially colored.

Onyx is one of the birthstones for the month of July. It is associated with the zodiac sign Leo.

The word onyx is also used to refer to a very deep black color (jet-black) or describe things that are that color.

Example: In this ring, the sparkling diamonds are a perfect contrast to the jet-black onyx in the center.

Where does onyx come from?

The first records of the word onyx come from the 1200s. It comes from the Greek ónyx, meaning “nail,” “claw,” or “veined gem.”

Onyx is a variety of the mineral chalcedony, a kind of quartz. The gemstone known as sardonyx is another variety of chalcedony that’s reddish-brown with white layers.

The all-black variety of onyx is sometimes confused with the volcanic glass obsidian. It is also sometimes incorrectly referred to as Mexican onyx or onyx marble.

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What are some synonyms for onyx?

What are some words that share a root or word element with onyx

What are some words that often get used in discussing onyx?

How is onyx used in real life?

Onyx is common in jewelry. It’s best known for its all-black variety.

Try using onyx!

True or False?

Onyx is always jet-black.

How to use onyx in a sentence

British Dictionary definitions for onyx

/ (ˈɒnɪks) /

a variety of chalcedony with alternating black and white parallel bands, used as a gemstone. Formula: SiO 2
a compact variety of calcite used as an ornamental stone; onyx marble. Formula: CaCO 3

Word Origin for onyx

C13: from Latin from Greek: fingernail (so called from its veined appearance)
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

Scientific definitions for onyx

[ ŏnĭks ]

A type of chalcedony that occurs in straight and parallel bands of different colors, often black and white.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.