Back Óniz AN جزع (حجر كريم) Arabic اونيكس ARZ Oniks Azerbaijani Онікс Byelorussian Онікс BE-X-OLD Оникс Bulgarian Ònix Catalan Onyx Czech Onyx Danish

Onyx

This article is about the mineral. For the New York hip hop group, see Onyx (hip hop group). For other uses, see Onyx (disambiguation).
Onyx
Black onyx with concentric white bands
General
CategoryChalcedony variety (silicate minerals)
Formula
(repeating unit)		SiO2 (silicon dioxide)
Crystal systemTrigonal
Identification
Formula mass60.08 g/mol
ColorVarious
CleavageNone
FractureUneven, conchoidal
Mohs scale hardness6.5–7
LusterVitreous, silky
StreakWhite
DiaphaneityTranslucent
Specific gravity2.55–2.70
Optical propertiesUniaxial/+
Refractive index1.530–1.543
References[1][2]

Onyx is the parallel-banded variety of chalcedony, a silicate mineral. Agate and onyx are both varieties of layered chalcedony that differ only in the form of the bands. Onyx has parallel bands while agate has curved bands. The colors of its bands range from black to almost every color. Specimens of onyx commonly contain bands of black or white, or both.[1] Onyx, as a descriptive term, has also been applied to parallel-banded varieties of alabaster, marble, calcite, obsidian, and opal, and misleadingly to materials with contorted banding, such as "cave onyx" and "Mexican onyx".[1][3][4]

  1. ^ a b c Onyx, Mindat.org, retrieved 2015-08-22
  2. ^ "Onyx". gemdat.org. Retrieved 2015-08-22.
  3. ^ Manutchehr-Danai, Mohsen (2013). Dictionary of Gems and Gemology. New York: Springer. pp. 340–341. ISBN 9783662042885.
  4. ^ Schumann, Walter (2009). Gemstones of the World. New York: Sterling. p. 158. ISBN 9781402768293.

Rich TVX News Network Site

Rich TVX News Network Info

© MMXXIII Rich X Search. We shall prevail. All rights reserved. Rich X Search