onyx

Onyx is a typically black-and-white banded variety of agate, a silicate mineral. The bands can also be monochromatic with alternating light and dark bands. Sardonyx is a variety with red to brown bands alternated with black or white bands. The name "onyx" is also frequently used for level-banded (parallel-banded) agates, but in proper usage it refers to color pattern not band structure. Onyx, as a descriptive term, has also been incorrectly applied to parallel-banded varieties of alabaster, marble, calcite, obsidian, and opal, and misleadingly to materials with contorted banding, such as "cave

AI overview

Onyx is a semi-precious stone that is typically black and white in color, belonging to a family of minerals called agate, and it has been valued historically for decorative and ornamental purposes. The term "onyx" is sometimes misused to describe other banded stones like marble or alabaster, but properly refers specifically to the color pattern of the agate mineral itself rather than its band structure.

AI-generated from the Wikipedia summary — may contain errors.

Key facts

Mineral.boxtextcolor: FFFFFF
Mineral.boxbgcolor: 353935
Mineral.name: Onyx
Mineral.category: Tectosilicate minerals
Mineral.group: Quartz group
Mineral.IMAstatus: Variety of quartz (chalcedony)
Mineral.image: Agate-Quartz-49959.jpg
Mineral.alt: Black onyx with concentric white bands
Mineral.caption: Onyx with concentric banding
Mineral.formula: SiO2 (silicon dioxide)
Mineral.molweight: 60.08 g/mol
Mineral.color: Black and white; red to brown with black or white (sardonyx)
Mineral.system: Trigonal (quartz), Monoclinic (moganite)
Mineral.cleavage: None
Mineral.fracture: Uneven, conchoidal
Mineral.mohs: 6.5–7
Mineral.luster: Vitreous, silky
Mineral.streak: White

via Wikipedia infobox

Wikidata facts

Image: Onyx.jpg

Show 4 more facts

Commons category: Onyx
chemical formula: SiO₂
Mohs' hardness: 7
density: 2.659

Sources (5)

via Wikidata · CC0

~5 min read

Article

9 sections

Contents

Etymology
Varieties
Imitations and treatments
Geographic occurrence
Historical use
Culture
See also
References
External links

==Etymology== Onyx comes through Latin (of the same spelling), from the Ancient Greek (), meaning or . Onyx with pink and white bands can sometimes resemble a fingernail. The English word "nail" is cognate with the Greek word.